The Big Question Every Team Will Have to Answer This Winter

As we head into the off-season, there are a lot of different plans being made. Some teams are preparing to spend big on free agents, looking to upgrade their roster for 2018 without surrendering any talent. Others are looking to make win-now trades, eyeing upgrades currently on other teams. And a few teams are planning on being sellers, turning some big leaguers into players who might be more helpful when the team is ready to win.

But regardless of where a team is on the success cycle, every team is going to have answer the same question this winter. This question hangs over the evaluation of nearly every player in the big leagues, and will impact both what kinds of players a team will acquire, how they value them, or whether they feel their internal options are as good as what they can bring in from the outside. And this question has little to do with each player’s own abilities, yet might have a big impact on their expected performance.

In all 30 front offices, the off-season plan will be significantly impacted by one big variable: what kind of baseball should they expect to play with in 2018 and beyond?

While Major League Baseball continues to officially deny that the huge spike in home runs the last few years was primarily driven by changes in the manufacturing of the baseballs, the preponderance of the evidence suggests that the ball is the most likely factor.

I’m not one who buys into the idea that MLB changed the ball on purpose, but as has been shown, the allowed variance in ball specifications is so large that balls can still be within the allowable range and still behave very differently. My best guess is that some manufacturing change occurred during the 2015 season without anyone suspecting it would change the ball in a dramatic way, and to this point, MLB hasn’t yet told Rawlings to revert back to whatever the previous process was, so the league has been playing with a livelier ball for the last few years.

But as Ben Lindbergh noted last week, the issue has gotten enough publicity, with MLB players calling out the ball as a significant factor on World Series performance, that there’s no way the league can just continue a hands-off approach. There are too many players who believe the changes in the ball are messing with their livelihoods, and too many multi-million dollar decisions that depend on being able to accurately forecast the future, which can be undermined if the ball is constantly changing.

As Rob Arthur concluded this summer:

If the changes that made the ball bouncier and slicker are truly random, then baseball’s home run era could end just as suddenly as it began. MLB Commissioner Rob Manfred has said that fans like home runs and strikeouts. As the numbers of both whiffs and long balls are close to all-time highs, this must be baseball’s golden era. But to keep it that way, Manfred will likely have to impose tighter control over the ball’s construction than has been used in the last three years. The same random manufacturing changes that might have made it bouncier and slicker could just as easily make it stiff and air resistant — bringing back the year of the pitcher, and rendering all our juiced-ball detective work for naught.

Regardless of whether this happened accidentally or not, the league is likely capable of reducing the variation in manufacturing specifications to either ensure that this livelier ball is here to stay, or reverting back to something closer to what we had a couple of years ago. And what a team thinks the league might do about the ball could have a tremendous impact on what kinds of players they want to build their team around.

For instance, there are some free agents this winter that were pretty clear beneficiaries of the new ball. How a team evaluates Zack Cozart, for instance, depends almost entirely on what kind of ball one thinks the league might play with next year.

Up through the All-Star break at the 2015 season, which is when league home run rates really took off, Cozart had a career .245/.284/.375 line, good for a 77 wRC+. His career ISO was .130, as he’d hit just 42 home runs in a little over 2,000 plate appearances. But since the mid-point of the 2015 season, Cozart has hit .274/.346/.484 and put up a 116 wRC+. His ISO has spiked to .211, and he’s hit 40 home runs in just over 1,000 plate appearances. Half of his career +15 WAR have come in the past two seasons, at ages 30 and 31.

And while Cozart has made some changes to increase the number of fly balls he’s hit, the reality is that his results don’t really line up with how hard he’s hit the ball, and the best explanation for Cozart’s power spike is that he lives at the exact point at which the ball flying 5-10 feet further makes the most difference.

In a world where you don’t have to hit the ball that hard to get it over the fence, Zack Cozart is a star, a good defensive shortstop who makes contact and hits it just hard enough to rack up some extra base hits. But if the ball stops flying as far as it has the last few years, and Cozart loses a little bit of bat speed as he ages, he could very easily revert back to being a guy who is in the line-up solely for his defense. And how much does a team want to pay Cozart if they think a significant part of his success is dependent on MLB continuing to use a livelier baseball going forward?

The Reds’ decision to not extend Cozart a qualifying offer gives us a bit of a window into what they think the market will do with this information. If Cozart was going to sign for more than $50 million, extending him a QO would have been an easy choice, but the Reds are guessing that teams will be more conservative with power-spike guys, and that the market for Cozart’s services won’t be as strong as his results would suggest.

But if the Reds are right, and MLB ends up codifying standards that keep the ball lively, then Cozart could be a huge bargain for whoever bets on his warning track power continuing to play up in the future. And it’s not just Cozart. How much do you want to pay for Eric Hosmer’s offensive breakout if you’re not sure how much the ball contributed? What about Logan Morrison and Yonder Alonso, who were near-replacement-level players up until this year? Or even on the pitching side of things, Yu Darvish’s home run rate spiked this year; if the ball is going to change, is he a better buy than one might think based on his 2017 results?

The ball looms over the whole off-season. Before any decision is made, every front office is going to have to ask themselves just how much the new offensive environment of the 2016-2017 seasons had to do with the results the player put up, and the rewards weren’t evenly distributed, so it’s not as simple as adjusting the results for those league averages. And how well teams predict what the ball might do in the next few years could determine many of the winners and losers of this winter.

We hoped you liked reading The Big Question Every Team Will Have to Answer This Winter by Dave Cameron!

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If Cozart is exactly at the point where 5-10 feet makes the most difference, then wouldn’t hitters with similar exit velocity be right at that same point? He has performed over expectation even holding velocity constant. I’m not sure the best explanation for his power spike isn’t that it was simply a fluke.

I think the ball definitely has implications on player values, but not necessarily to the extent which this article seems to suggest. In 2017 Hosmer had a .351 BABIP and one of his lowest K rates. Alonso improved his swing plane. Darvish’s HR/9 was hardly even above league average. How much could any of this have to do with the juiced ball? Not to mention the fact that the ball was “juiced” in 2016, too, a year in which Hosmer and Alonso combined for -0.6 WAR, and Yu Darvish looked exactly like Yu Darvish even right after missing an entire season.


You’d want to look at fly ball EV, as most players have significant variances between LD, GB and FB EV’s. And then to FB%.

A player with similar FB EV and FB% as Cozart should see similar benefits .. in the same park. Remember Cozart plays in The Great American Small Park.

A hitter with similar fly ball profile might also benefit the way Cozart has with the Reds. Cozart’s same benefit may not translate as well to parks with less generous dimensions.

Ben Lindbergh wrote a great article to explain the home run surge on the Ringer this summer, and compared it with the end of the Dead Ball era, where HRs increased over 3 consecutive seasons due to linked factors:

Year 1: Due to WWI shortages, baseball started using Australian wool yarn instead of American. This wool was bouncier, and the ball travelled better. HR went up marginally.

Year 2: The Dead Ball era officially ended and baseball instituted the process of removing the ball from play as soon as it was dirted or scuffed in any way. Offense went up significantly, especially XBH, as hitters could see the ball better and it had better aerodynamic performance. HR went up further.

Year 3: Players realized that the game had changed. More players started intentionally trying to hit home runs as a form of offense and abandoned dead-ball era strategies (bunting, Baltimore chop hitting, etc) HR surged further; the league leader was now 3x what it was in Year 0.

In modern baseball, the factors are:

Change to the ball (late 2015 different than prior, but late 2015-current unchanged)

Change in hitting philosophy for some players, in part driven by data

Overall awareness that this strategy is more effective, leading to more aggressive adoption by more players, and more widespread effects.

The ball didn’t change from 2016 to 2017. But HR went up further, significantly, because more guys are trying to take advantage of it now, and the data is there to help them do so more easily.


I’ve spent a lot of time importing and breaking down the data behind guys outperforming their xwOBA. I found the correlations, in order, tend to be:

1. Ball park – cheap HRs mostly
2. Foot speed – lots of infield singles, more doubles
3. Spraying the ball – harder to defend
4. Being LHed – more infield singles and doubles

Luck seems to fall right in the middle as a cause.

Dave T
Dave T

I agree that Cozart would be a tough player to evaluate with plenty of question marks even absent questions about the ball.

He’s a 32 year old shortstop who has played a total of 243 games the last two seasons after playing 53 games in 2015. His time on the disabled list has been caused by a variety of knee and quad ailments, including surgery on his right knee in 2015. Other than his 5 WAR performance in 2017, he’s totaled more than 2 WAR in two of his six seasons: 2.5 WAR in 2016 and 2.3 WAR in 2012.