ChatGPT Guidance on projecting batting average

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Default (GPT-3.5)

User
To project a MLB players batting average, what are the most predictive metrics to use in a formula?

ChatGPT
To project a Major League Baseball (MLB) player’s batting average, you can use a combination of both traditional and advanced statistics. While batting average is a relatively simple statistic, using more advanced metrics can provide a more accurate projection. Here are some key metrics to consider:

Historical Batting Average: Start with the player’s historical batting average data over the past few seasons. Recent performance is often a good indicator of future performance.

Plate Discipline Metrics:

Walk Rate (BB%): A player with a high walk rate can have a better understanding of the strike zone and may be more selective in their at-bats.
Strikeout Rate (K%): A lower strikeout rate indicates that a player makes more contact, which can positively impact their batting average.

Batted Ball Profile:

Batting Average on Balls in Play (BABIP): BABIP measures how often a batted ball becomes a hit when it’s put in play. A player with an unusually high or low BABIP may experience regression towards the mean.
Line Drive Rate (LD%): Line drives typically result in hits more often than other types of batted balls.
Ground Ball Rate (GB%) and Fly Ball Rate (FB%): A player’s batted ball profile can affect their batting average. For example, ground balls are more likely to result in hits than fly balls.

Quality of Contact Metrics:

Hard-Hit Rate: Measures the percentage of batted balls that are hit with a high exit velocity, which can lead to more hits.
Soft-Hit Rate: Conversely, a high soft-hit rate can indicate weaker contact and potentially lower batting average.

Pitch Recognition and Plate Coverage:

Swinging Strike Rate (SwStr%): A lower swinging strike rate suggests good pitch recognition and plate coverage.
Contact Rate (Contact%): A higher contact rate means the player is making more contact with the ball.
Splits and Matchup Data:

Platoon Splits: Consider how a player performs against left-handed and right-handed pitchers.
Performance Against Different Pitch Types: Some players excel against certain pitch types while struggling against others.
Ballpark Factors: Take into account the ballpark where the player will be playing. Some ballparks are hitter-friendly, while others are pitcher-friendly.

Age and Career Trajectory: Younger players may still be developing, and older players may be in decline. Consider a player’s age and career trajectory.

Injury History: Injuries can significantly impact a player’s performance and should be factored into projections.

Regression Analysis: Use statistical models that incorporate these metrics along with historical data to project future performance.

Remember that no projection system is perfect, and there is always an element of uncertainty in sports statistics. It’s important to continually update your projections throughout the season based on a player’s performance and any changes in their approach or circumstances. Additionally, context matters, so consider the specific player and situation when making projections.

User
Wow! that is a lot of metrics. Which of these are the five most predictive relative to the others?
ChatGPT
While all of the mentioned metrics can contribute to predicting a Major League Baseball (MLB) player’s batting average, some are generally more predictive than others. The importance of specific metrics can vary depending on the player and their unique characteristics, but here are five metrics that are often considered among the most predictive for batting average:

Historical Batting Average: A player’s recent history of batting average is usually the most predictive factor. Players tend to maintain a level of consistency in their performance, so their past batting averages are a strong indicator of what you can expect in the future.

Batting Average on Balls in Play (BABIP): BABIP is a key metric for evaluating how lucky or unlucky a player has been in terms of the outcomes of their batted balls. It’s often used to identify potential regression or progression in batting average. Players with abnormally high or low BABIPs are likely to see those numbers move closer to the league average over time.

Plate Discipline Metrics (Walk Rate and Strikeout Rate): A player’s walk rate and strikeout rate are good indicators of their ability to make contact and their understanding of the strike zone. A lower strikeout rate and a higher walk rate often correlate with a better batting average.

Batted Ball Profile (Line Drive Rate, Ground Ball Rate, Fly Ball Rate): The type of contact a player makes can significantly impact their batting average. Line drives tend to result in hits more often than other types of batted balls, so a high line drive rate is predictive of a higher batting average.

Hard-Hit Rate: Hard-hit rate measures the percentage of batted balls hit with high exit velocity. Players who consistently make hard contact are more likely to get hits, making this metric a strong predictor of batting average.

These five metrics provide a solid foundation for projecting batting average. However, it’s essential to consider these metrics in combination, as no single metric can provide a complete picture of a player’s batting ability. Additionally, contextual factors, such as a player’s age, ballpark, and matchups, should also be taken into account when making predictions. Baseball is a complex sport, and multiple factors can influence a player’s performance.

ET

Thanks! I would like to rank my player projections +/- from the batting average for the top 400 players in plate appearances. I would like 1.00 to represent a dead average projected batting average, and better player projections to achiever a score such as 1.20. Vice versa for the worst projections, e.g., .85, for example. Can you provide an excel formula with the top five metrics you just provided for my spreadsheet?

ChatGPT

Certainly, you can create a scoring system in Excel to rank player projections relative to the league average batting average, with 1.00 representing an average projection. You can assign weights to each of the five metrics you mentioned and calculate an overall score for each player. Here’s an example of how you can set up this scoring system in Excel:

Assuming your player projections for the top 400 players are in columns B to F (one column for each metric) and that your league average batting average is in cell G1:

  1. First, calculate the z-score for each metric. The z-score measures how many standard deviations a player’s performance is from the mean.In cell H2 (for the z-score of Historical Batting Average), enter the formula:swiftCopy code=(B2-G$1)/STDEV.P($B$2:$B$401) Drag this formula down to calculate z-scores for all players for this metric. Repeat this process for each of the five metrics, placing the z-scores in columns H to L.
  1. Next, assign weights to each metric. Let’s assume you want to assign equal weights to all five metrics.In cell M1 (for Weighted Score), enter:cssCopy code=(H1+I1+J1+K1+L1)/5 This formula calculates the average z-score across all five metrics.

3. Finally, calculate the overall score for each player relative to the league average batting average. Assuming you want 1.00 to represent an average projection, enter the following formula in cell N2 (for Overall Score):swiftCopy code=1+((M2-AVERAGE($M$2:$M$401))/STDEV.P($M$2:$M$401))

This formula calculates an overall score for each player, with 1.00 representing the league average. Drag this formula down to calculate scores for all players.

Your spreadsheet should now have an “Overall Score” in column N that represents how each player’s projected batting average compares to the league average, with 1.00 as the average projection. Players with scores above 1.00 are projected to perform better than average, and those below 1.00 are projected to perform worse than average. Adjust the weights for each metric in the “Weighted Score” calculation if you want to give certain metrics more or less importance in your projections.

User
OK. Based on the predictive quality of each metric, how would you recommend I weight each of the five?
ChatGPT

The optimal weightings for each of the five metrics can vary depending on the specific data and the context of your player projections. However, you can consider a balanced approach based on the general predictive quality of each metric. Here’s a suggestion for assigning weights to the five metrics:

Historical Batting Average: This is often the most reliable predictor, so you might assign it a higher weight. A weight of 30% is a reasonable starting point.

Batting Average on Balls in Play (BABIP): BABIP is a valuable metric for assessing luck and regression potential. Assign it a moderate weight, such as 20%.

Plate Discipline Metrics (Walk Rate and Strikeout Rate): Plate discipline metrics can be quite indicative of a player’s ability to make contact and select pitches. Give them a combined weight of 20%.

Batted Ball Profile (Line Drive Rate, Ground Ball Rate, Fly Ball Rate): The type of batted balls a player generates can influence their batting average. Assign a weight of 15% to this category.

Hard-Hit Rate: This metric measures the quality of contact and is also significant. Give it a weight of 15%.

So, your weighted score formula in cell M1 would look like this:

scss
Copy code
=(H1 * 0.30 + I1 * 0.20 + (J1 + K1) * 0.20 + L1 * 0.15) + (M2 * 0.15)

This assigns higher weights to the more predictive metrics like historical batting average, BABIP, and plate discipline while still considering the influence of batted ball profile and hard-hit rate. These weights provide a balanced approach, but you can adjust them based on your specific data and the relative importance you believe each metric holds for your player projections.

User
Thank you, ChatGPT!

Using ChatGPT to craft HR projections for the 2024 MLB season

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The MLB season will be over in a week or so. That means the 2024 season is just around the corner!

I am using ChatGPT for some insight into my home-made projections while I await Steamer. Here’s what she says about projecting a player’s HR total in response to the following query:

ME: In MLB fantasy baseball, what are the best predictive metrics like barrel rate to predict a player’s homerun total the following season?

In MLB fantasy baseball, predicting a player’s home run total for the following season can be challenging, but there are several metrics and factors you can consider to make more informed projections. While barrel rate is a valuable metric, it’s important to combine it with other statistics and factors to create a well-rounded projection. Here are some key metrics and considerations to help you predict a player’s home run total:

Barrel Rate: Barrel rate measures how often a player makes ideal contact with the ball, resulting in the best combination of exit velocity and launch angle for home runs. A high barrel rate indicates a player’s ability to consistently hit the ball hard and at an optimal angle. This metric can be a good indicator of power potential.

Exit Velocity: Exit velocity measures how fast the ball comes off a player’s bat. Players with consistently high exit velocities are more likely to hit home runs because they generate more power. Statcast data provides exit velocity information.

Launch Angle: A player’s launch angle, or the angle at which the ball leaves the bat, can significantly impact their home run production. Players who consistently hit the ball at launch angles that optimize power are more likely to hit home runs.

Historical Performance: Review a player’s past seasons to see if they have a history of hitting for power. Look at their home run totals over the last few seasons and their career as a whole. Consistency in power production is often a good sign.

Plate Discipline: A player’s plate discipline can also affect their home run production. A batter who has a good eye and swings at pitches within the strike zone is more likely to make solid contact. Metrics like O-Swing% (percentage of pitches swung at outside the strike zone) and Z-Swing% (percentage of pitches swung at inside the strike zone) can be informative.

Ballpark Factors: Consider the ballpark in which the player will be playing. Some ballparks are more hitter-friendly and can boost a player’s home run numbers.

Age and Health: Younger players may continue to develop power, while older players may see declines. Additionally, a player’s health and injury history can impact their ability to hit for power.

Team and Lineup Context: The quality of a player’s supporting cast and their spot in the lineup can affect their RBI and run-scoring opportunities, which can indirectly impact home run production.

Offseason Changes: Pay attention to any changes in a player’s offseason training regimen, swing adjustments, or approach changes. These factors can influence power production.

Statistical Models: Some fantasy baseball analysts use statistical models and projections to estimate a player’s future performance. These models often incorporate various metrics and historical data to make predictions.

Keep in mind that while these metrics and factors can be helpful, there are no guarantees in fantasy baseball. Players can experience unexpected fluctuations in performance due to various factors, including luck and variance. It’s essential to use these metrics as part of a comprehensive analysis and not rely solely on one statistic to make your predictions.

These are some good suggestions. Let’s see what she says about an Excel formula to generate a useful formula to use with projected plate appearances. Here’s my query:

Those were some good suggestions for my MLB projections. Now I need to formulate an Excel formula to crunch some of those metrics. Can you suggest an excel formula to use the following metrics: barrel rate; launch angle; exit velocity; and plate discipline. Also, please add the metric OPS to the list. I would like to generate a number that is + or – 1.00. In my example, 1.00 is the average number of homeruns for MLB players who had at least 400 Plate Appearances.

To create an Excel formula that calculates a projected home run number based on the metrics you mentioned (barrel rate, launch angle, exit velocity, plate discipline, and OPS), you can use a weighted average approach. You’ll assign weights to each metric based on their importance and then sum up the weighted values to generate a projection. Here’s a formula that you can use as a starting point:

Excel=(((BarrelRate * WeightBarrelRate) + (LaunchAngle * WeightLaunchAngle) + (ExitVelocity * WeightExitVelocity) + (PlateDiscipline * WeightPlateDiscipline) + (OPS * WeightOPS)) – AverageHR) / StandardDeviationHR

In this formula:

BarrelRate, LaunchAngle, ExitVelocity, PlateDiscipline, and OPS should be replaced with the actual values for each player.
WeightBarrelRate, WeightLaunchAngle, WeightExitVelocity, WeightPlateDiscipline, and WeightOPS are weights you can assign to each metric. These weights should add up to 1. You can adjust them to emphasize the importance of each metric in your projections.
AverageHR should be replaced with the average number of home runs for MLB players who had at least 400 Plate Appearances.
StandardDeviationHR can be the standard deviation of home runs for the same group of players. This helps you scale the result to a range of approximately +1.00 to -1.00.
Here’s a step-by-step guide on how to use this formula:

Calculate the average and standard deviation of home runs for MLB players with at least 400 Plate Appearances.
Assign appropriate weights to each metric based on their importance.
Replace the placeholders in the formula with the actual values for each player and the calculated average and standard deviation.
The result will give you a projected home run value for each player, which you can use for your fantasy baseball projections.
Please note that this formula is a basic starting point and may need further refinement based on your specific analysis and data. Additionally, consider normalizing the metric values if they are on different scales to ensure that no single metric dominates the projection.

This is great. Based on your knowledge of these various metrics and their historical predict value, what weights would you assign to each metric?

Assigning weights to each metric depends on your analysis and how much you believe each metric contributes to a player’s home run production. It’s essential to consider historical predictiveness, but also keep in mind that the effectiveness of these metrics can vary from season to season and from player to player. Here’s a general guideline for assigning weights based on their historical predictiveness:

Barrel Rate: Barrel rate is a strong indicator of a player’s ability to make solid contact, and it tends to correlate well with power production. Assigning a relatively high weight to barrel rate, such as 0.3 or 0.4, can be a good starting point.

Launch Angle: Launch angle is crucial for determining the trajectory of the ball. Assign a moderate weight, such as 0.2 or 0.3, as it can significantly impact home run production.

Exit Velocity: Exit velocity measures the speed of the ball off the bat and is an important component of power. Assign a weight similar to launch angle, such as 0.2 or 0.3.

Plate Discipline: Plate discipline metrics like O-Swing% and Z-Swing% indirectly impact power production by influencing a player’s ability to make solid contact. Assign a lower weight, perhaps 0.1 or 0.2, as plate discipline alone may not be as predictive of home runs.

OPS: OPS (On-base Plus Slugging) is a well-rounded metric that includes both on-base percentage and slugging percentage. It captures a player’s ability to get on base and hit for power. Assign a moderate weight, such as 0.2 or 0.3, to OPS.

Remember that these weights are just a starting point, and you may need to adjust them based on your analysis, data, and the specific context of the season. It’s also a good idea to track the actual performance of the players you project to see how well your weights and formula are working, and then make adjustments accordingly. Over time, you can refine your weights to improve the accuracy of your projections.

Author: ChatGPT Title: “Predicting MLB Fantasy Baseball Home Run Totals: Key Metrics and Factors”

Should I trust @EnoSarris ‘s Pitching+ Model? @ven_armbarn @PileOfDial @InTheCutFantasy

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There is a lot of buzz this year about Eno’s new Stuff+ pitching model. You can find the tables (sort of) by subscribing to The Athletic and finding Eno’s author page. Scrolling around a bit will lead you to a few recent articles with pitching rankings. Based on my anecdotal observations, it seems like a lot of fantasy competitors are using that model for 2023 drafts to evaluate pitchers.

I get it. Everyone wants to find an edge. And a model that measures movement of individual pitches, and other granular data, to mathematically find pitchers likely to outperform ADP and/or projections, gives you an edge. I love Eno’s work. A journalist, he is talking to MLB pitchers about their craft. I’ve been following Eno on Twitter for years. Bringing his inside knowledge of pitching into a mathematical model, well that sounds like a great endeavor for fantasy baseball geeks like myself.

With all this inside information, I checked to see how Eno performed in the 2022 @NFBC Draft Champions contests

Eno entered three DC contests last year and his teams were ranked as follows: 315, 2,342, 2,872, Not bad.

One of the hottest and best fantasy baseball podcasts to emerge this year is In The Cut with John Fish and Ryan Venancio. I’ve listened to all of the episodes. Ryan is heavily reliant upon Eno’s Stuff rankings. Ryan drills deep into pitch mixes and induvial pitch performance. It’s great. You shouldn’t miss the fantasy commentary. Ryan has confidence, and strong opinions on starting pitchers. Many of them seem to derive from Eno’s work.

Based on this, I assumed Ryan relied upon Eno’s Stuff+ for his 2022 DC season drafts. [UPDATE: the assumption was wrong. Ryan tweeted as follows: “I only started using Eno[‘]s pitching metrics at the very end of draft season last season….”] Ryan said 2022 was his first competing in the NFBC. He performed better than I did in my first NFBC year. In 2022, Ryan entered 8 DC contests. Only his last DC drafts are relevant to evaluate Eno’s rankings. His DC overall teams were ranked 550, 958, 1,555 (#272), 1,960, 2,528, 2,958 (#352), 3,601, 4,223. (There were 4,815 teams in the contest.) I bolded Ryan’s last two DCs. The bolded contests were the contests he may have used Eno’s 2022 pre-season pitching rankings. Probably, this sample is too small to draw any conclusions about Eno’s projections. However, Ryan said he will be using them for his 2023 draft process so we will be a good test for next year and Ryan is paying the price for us!

By contrast, I didn’t rely on Eno’s model at all for my 2022 DC drafts. My process was more focused on K%, BB%, and SIERA. I also looked at SSW data on individual pitch basis, velo, etc. I spend a lot of my time analyzing team context as well. I use my process to differentiate my targets from other pitchers around the fluctuating market ADP .

I entered 9 DCs last year with decent results: 489, 490, 686, 761, 986, 1,308, 2,218, 2,320, and 4,296. My performance last year was almost entirely successful, to the extent it was, based on my pitching SGP. Based on this, I think I’ll stick to my pitching process this year. My goal this year is to improve my hitting SGP. If I do that, then I think I can cash more often than last season.

I also want to see how Eno’s new Stuff+ pitcher rankings works out for 2023 before I go all in betting on it.

That said, some of my 2023 targets are on Eno’s list. Based on 2023 fantasy group think and the trends I am seeing now, I think Eno’s Stuff+ pitchers will move up in ADP. Therefore, I have identified my targets that are coincidentally on Eno’s list, I am bumping them a round to avoid snipers.

Find an advantage. OPS splits. #fantasybaseball @NFBC #DraftChampions @JeffWZimmerman @SmartFantasyBB

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The Process , by @JeffWZimmerman and Tanner Bell, aka @SmartFantasyBB is out. Buy the book. It is full of invaluable advice.

Quoted above is a paragraph from the book. The book goes into great detail in all aspects of the game. This general advice from the introduction grabbed my attention. Searching for an advantage over my competitors in my draft prep is a key component of my efforts to improve.

It’s draft season. It is basic for fantasy players to find a good projection system like Steamer and follow it. If we do so, we probably get a slightly above-average team. If you pick the right projection system or maybe even design your own system, you might even cash in a decent percentage of leagues. But most all of your competitors are using projections. If everyone else is doing it, then how is strictly following a projection giving you much of an advantage?

First, one must understand what projection systems are doing. They are each varied in their approach. However, the general idea is for the system use a player’s past few years of performance, with the most recent years weighted more heavily. The creators of these systems are secretive about their specific methodologies, but I assume they use seasonal performance, usually 3 – 5 years.

One of the tricks I’m trying this year is use of the seasonal split data for 2022 season to identify players who might deviate. For one such analysis, I used the OPS (on-base percentage plus slugging) metric.

To compile the data, I just downloaded the first and second half split season information from Fangraphs. I cut and pasted the data into one worksheet and sorted by the unique PlayerID. After adding some conditional formatting, I got a worksheet that looked like this:

Then, I ran an Excel pivot table on the data and sorted by the biggest standard deviation in OPS. The table showed which players had the biggest splits in OPS between their first and second half of the 2022 season. That sorted table looked like this:

It made it easier to identify players for a deep dive. Was something implemented during the player’s 2022 season that gives him the potential for a breakout 2023 season? Projections don’t account for things like changes in approach–aggressiveness, pulling, elevating, stance changes, etc. If you can identify players who implemented an actionable change in approach, you have a shot at finding players who will outperform or underperform the projection. These guys become targets or fades when drafting.

I love a redemption story: Why I draft Jonathan Singleton in @NFBC #DraftChampions

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Back in 2012, Jonathan Singleton was ranked as baseball’s top power hitting first base prospect. On June 2, 2014, before taking a single plate appearance, the Astros signed Singleton to a history-making 5-year contract. The $10 million deal was the first time a team ever signed a player to a long-term contract before he played a single MLB game.

Unfortunately, the 22-year old Singleton got caught up in a marijuana addiction. The drug, then illegal nearly everywhere at the time, cost him dearly. His performance declined. He tested positive for the drug several times, and he was suspended twice before checking into a 30-day a rehabilitation facility. Addictions are nasty things. Singleton fell off the wagon again in 2018, and MLB hammered him with a 100 game suspension. The once promising career for the young, slugging, California first baseman appeared to be over.

But Singleton wouldn’t allow the addiction to beat him. In 2021, he resumed his career. He made a big splash in the Mexican Baseball League with the Red Devils, where he hit .321 while mashing 15 home runs. The performance led to a spring training invitation with the Brewers for last season. Singleton didn’t make the Brewers team in 2022, but he did secure a minor league contract with their Nashville AAA team.

Singleton performed admirably in AAA. He blasted 24 bombs and registered a WRC+ of 118. His K% in Nashville was concerning, 27.7%, but not high enough to eliminate him from my personal fantasy baseball draft screening process. His BB% was fantastic at 20.1%. That redemption story, the power, and his prospect pedigree makes Jonathan Singleton an intriguing late round DC pick.

Singleton’s chance of playing time for the Brewers in 2023 is not without hurdles. Here is a Fangraphs’ chart showing the Brewer’s projected starting lineup and bench:

Singleton is a LHB and will have to compete with both the oft-injured Winker and popular Rowdy Tellez for playing time. On top of that, Hiura also plays first and is a reverse splits guy meaning he hits RHP better than LHP. But both Winker and Hiura have known recurring flaws so either one or both could fail opening the door for regular RHP at-bats for Singleton.

I wouldn’t advocate drafting him before round 40, but you could make a worse pick than a mid-40th round Singleton.

Zac Gallen’s Second Half. #DraftChampions

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Posting a 1.49 ERA second half, over 90 innings of work, is impressive. The FIP was just 2.09. Health is the only issue. Gallen flirted with an elbow issue in early 2021, but it was not his UCL and he is clearly over that issue.

Gallen’s four-seam fastball and curve are hard to hit. The decline in ERA began as the curveball usage increased. Pitch mix change? He could be an ace if the D-backs talented young team improves.

The sucking risk of CJ Cron

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Drafting Rockies hitters is usually a good strategy. However, 1B Cron may not be one I adopt this season. He does have a contract through 2023. Therefore, his playing time seems secure on the surface. However, Cron’s 30 day rolling average OPS declined to below .650 by the end of 2022. Looks like maybe he can be victimized by sliders. How long will the Rockies stick with Cron if his OPS does not improve before they start experimenting with prospects Elehuris (AAA WRC+ 131) or Toglia (AA/aaa WRC+ around 130)? Both prospects had 2022 cups of coffee. (Montero PA 185, Toglia PA 125)