Determining Hitter Profile Changes

Right now I am in the middle of writing preseason player profiles for several publications. Like most people, I examine a player’s stat page for most of the information. Additionally, I have access to our database and have created some cheat sheets to help with looking for possible changes in a hitter’s profile to help explain stat changes like a significant bump in home runs. Today, I’ll start with making my hitter sheet available and go over a few players with the information.

I find hitters to be the tougher than pitchers to determine if changes in production are from a new approach or from just plain luck. To help find such changes in approach, I determine changes in several metrics which would point to an overall talent adjustment. The stats I examine are:

Swing based
Pull%
GB%
Hard%

Eye base
BB%
K%

With each variable, I found the league-wide standard deviation of change from season-to-season. With the standard deviations, I added together several individual variables to find similar trends (e.g. hitting for more power). Additionally, I combined the overall values together for one “change” metric (average value is 4.1, median: 3.7).

I usually start with this change value when looking to see if a player has made a change I should bring to light. Most of the time the change is obvious, but other times it is small changes to several categories which don’t seem like much by themselves but can add up to a significant change in production.

I have grouped the above stats into three more categories. The first is a power profile. For this category I looked for hitters who pulled the ball more (Pull%), hit the ball in the air (low GB%), and hit it harder (Hard%). If a batter has a home runs jump with none of the above factors, I would be skeptical of him repeating the power increase.

Next, I created a profile for speed or spray hitter. Not everyone can hit home runs (e.g. Billy Hamilton), so this approach may be a good fit for weaker, faster players. I didn’t include Hard% in this value because hitting the ball hard or softer doesn’t matter for the change I am looking to find.

The final category is an eye value. It is just the combined change in walk and strikeout rates.

I have gone ahead and combined all the values into one spreadsheet with all the values (2012 to 2016, min 50 PA per season). Enjoy.

Since it is shortstop week here at RotoGraphs, I will go ahead and go over some of the them who top the change rankings.

Stephen Drew (7.1 change, +5.3 in power profile)

Drew played sparingly in 2016 (165 PA), but ended up crushing right-handed pitching (.283 ISO). His hitting profile changed quite a bit from the previous season with his groundball rate dropping ~6% points and his hard hit rate almost doubling from 22% to 41%.

Another change with Drew is his overall eye value didn’t change much, but the individual values did with a 1% point increase in walk rate and 2% point increase in strikeout rate. This combination is common with power hitters as they wait for the right pitch and then try to crush it.

I am not sure how much to believe the changes since he was almost exclusively used versus righties. He does look to be a nice daily lineup or DFS play for the days he does get a start with his new team.

Jose Reyes (7.1 change, +3.5 in power)

Reyes’s changes are similar to Drew’s with more power and a steady overall eye value with his K% and BB% both increasing.

Jonathan Villar (6.8 change, +1.6 speed, +1.9 power)

Villar has the distinction of having a both a positive power and speed grade because his Hard% increased so much (25% to 35%). Most of his changes can be traced back to not swinging at pitches out of the strike zone (28% to 23%). Since he is not chasing the pitches, he is making better contact, as seen by the Hard% increase, and thereby walking a ton more (8% to 12%). For next season, I would look to see if he continues this plate discipline as it helps his overall game.

Jed Lowrie (6.7 change, -5.5 power, -1.2 eye)

Finally, a player headed in the wrong direction. Almost all of Lowrie’s struggles can be linked back to early May when he fouled a ball off his foot. Before the injury, he was hitting .302/.341/.345 and when he did play after the injury, he hit only .243/.300/.311. I will blame the drop off on the injury.

We hoped you liked reading Determining Hitter Profile Changes by Jeff Zimmerman!

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Jeff, one of the authors of the fantasy baseball guide,The Process, writes for RotoGraphs, The Hardball Times, Rotowire, Baseball America, and BaseballHQ. He has been nominated for two SABR Analytics Research Award for Contemporary Analysis and won it in 2013 in tandem with Bill Petti. He has won three FSWA Awards including on for his MASH series. In his first two seasons in Tout Wars, he's won the H2H league and mixed auction league. Follow him on Twitter @jeffwzimmerman.

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