clock menu more-arrow no yes mobile

Filed under:

Some Early Season MLB Stat Trends

Here are 10 Tables telling the story of 2021 so far

I wanted to take a look at how early season stats in 2021 compare to the recent decade. The first thing I decided was I wanted primary focus on March/April numbers vs. March/April . So all comparisons are for the first month of the season. Don’t let the preponderance of charts scare you. There are no difficult or esoteric concepts here.

A few caveats to note

  • Sometimes the season starts in March, and therefore there will be more games played by the end of April.
  • Some years the April weather is a lot worse, with more cancellations (2012 & 2015 for example).
  • Today is just April 28th and there are still 3 days left in the month, but my article is due today ;)
  • I do not include 2020 as there was no April, and it’s just not apples to apples to include the first 4 weeks of 2020 that took place from July 24th to August 21.

TABLE 1: Run Scoring

So lets just start with the basics. Runs per game. I broke out the averages from 2011-15, pre rabbit ball, 2016-2019, rabbit ball, and then 2021 at the bottom. I also show the Mar/April numbers against the full season numbers and the difference. I think most people go by the old axiom that offense increases as the weather warms up. But if 5 of the previous 9 seasons the opposite was true. On the other hand, in 3 of the last 4 years scoring ended up significantly higher than April numbers.

In any case, we can see scoring is down from the previous 4 Mar/April periods, but similar to the 5 years before that. Whether or not we see large increases as the weather warms up remains to be seen. It’s obviously not a given and we shouldn’t just make that assumption going forward.

Tables 2 & 3 : Balls in Play vs. 4 True Outcomes (HR, K, BB, HBP)

Here you can really see in both the percentages and the graph the inexorable march in the increase in 4 True Outcomes and the converse decline in balls in play. Defenders get to run around and impact the play about 10% less than they did just 10 years ago, making good or great defense less impactful. Despite any efforts on the part of MLB this this trend has actually accelerated ! From the next table you can see that while all 4 components of the 4 TO are up, by far the biggest factor remains strikeouts

Tables 4 & 5 : 4 TO Breakdown

Already the biggest component of 4 TO, Strikeouts are up a whopping 32% since 2011. Walks are up slightly, especially compared to 2012-215. HBP have nearly DOUBLED, but are a minor component in the total. They are however a symptom perhaps. Homeruns are back to 2017, but still much higher than they were just 10 years ago. Of course on a percentage basis homers don’t make up a large chunk of 4TO, but they do have a large impact to the overall game.

Run scoring is similar to what it was 8-10 years ago, but the MAKEUP of the game has drastically changed in a very short period of time.

Table 6: Pitch Velocity

NOTE: Fangraphs has already made adjustments to account for the differences in measurement of release out of hand vs. part way to the plate. So this chart is indeed apples to apples

The average Fastball is 2MPH quicker, the average Curve is almost 3 MPH quicker, while sliders and cutters are 1 MPH. Even the Changeup is 2MPH faster.

Nothing correlates stronger to swing and miss, and therefore strikeouts than velocity. WHY are pitchers able to throw so much harder ? It’s a combination of different training, and also different usage. Simply starters go max effort for shorter periods of time and more relievers coming in going max effort for an inning at a time are driving up these velocity numbers and the strikeouts. It’s not really due to the hitters selling out for the homer. See below

Tables 7 & 8: Batted Balls

Continuing the thoughts from the above section, I have some pretty strong opinions on this. We often hear people complaining about the hitters trying to alter their launch angles and approach, and that is the root of all evil in the game. I don’t think that’s a major factor on a league wide basis. Sure there have been a few notable guys that went through big changes that help fuel that narrative, such as J.D. Martinez and Justin Turner. But overall, that’s just not as big a factor as many people think. Why do I say this ? Well simply look at the data above. Fly ball percentage, and FB and Line Drive percentage combined have increased less than 2%. It’s a change, but it’s just not that big.

I believe that players swing planes are really hard to change. There are a few that can change them. But for the most part, a hitters natural swing plane will remain the same throughout his career.

Now hitters can choose to swing harder, and I’m not saying that choice is a zero factor. But look at the HR per Fly ball % and the Hard Hit %. Those both literally jumped overnight right after the all star break in 2015:

Thru 7/14/2015. HR/FB 10.7%, Hard hit 28.6%

From 7/15 - 10/1 HR/FB 12.1%, Hard hit 29.2%

Without question, MLB screwing with the ball caused the jump in homers and hard hit rates. It appears they might have dialed that back “successfully” but only to 2017 levels, not pre 2015 all star break levels.

Table 9 Batting Avg and BABIP

With fewer balls in play year by year, and strikeouts increasing , batting average has been gradually dropping. League OBP managed to stay up thanks to slight increases in walks and HBP. But so far this year, B.A. and it’s cousin, BABIP, have cratered completely and nothing is able to make up for that. BABIP is down most likely due to shifts as much as anything else.

Teams have gone from shifting 10% of the time in 2015 to roughly 33% of the time last 2 years. Meanwhile BABIP with shift on is .272, and BABIP without the Shift is typically around .300.....ALTHOUGH so far in 2021 even without the shift BABIP is only .291. I’m not sure what’s going on there. But make no mistake. Shifts work at reducing hits on balls in play.

However, with the shift on slugging % and homers and extra base hits go UP 30 Points on average since 2015 ! That is a huge difference ! That IS a choice the hitters clearly make. They can’t hit through the shift, so they hit over it, and it’s been an effective strategy.

Table 10 Time of Game

Finally, everybody’s favorite. Games take 17 minutes longer to play than they did just a decade ago. The added time is all dead time, not quality time. While there are more pitches being thrown than ever, there is less action, fewer balls in play, less running and fielding, and more time in between pitches as well. Dead time. And if things don’t change, soon to be dead sport.


The biggest negative trends and changes to the game , primarily strikeouts, reduced balls in play and hits, and lengthened slow paced games , are all increasing at ever rapid rates. So far MLB has been completely ineffectual in bringing about any ways to improve the situation.

I often link back to THIS ARTICLE written several years ago. Everything in it pretty much still holds true. We need a pitch clock, and we need to keep batters in the batters box. Separate from the pace of play benefits, having a pitch clock and keeping batters in the box will make it necessary for pitchers to ease off the max effort and pitch to contact more. The batters will need to be ready to hit much more quickly and would need to try to put the ball in play more.

I would add limiting shifts at this point. I don’t think they should outlaw shifts completely. But they could put a limit on how many times per game a manager can use one. For example: 3 shifts allowed per game, no more than 1 shift on any one batter. Make it strategic, much like mound visits and replay challenges:

Before the league moves the mound back with a ton of unintended consequence, put in the damn pitch clock. Enforce the rules as originally written and designed first and see how that works. If it still doesn’t help, then go on to more radical changes if necessary. That’s my story, and I’m sticking to it.