There are several great stats out there that can tell how well a player is hitting, but they don’t tell us who is getting the hits when it matters most*.
For example, most stats will treat a home run hit in the 9th inning of tie game the same as one hit in the 8th inning of a game that is 12-0. And while both home runs are (for the most part) equally indicative of how well the player is hitting and will hit, clearly, one is more important than the other to the team.
That’s where WPA (Win Probability Added) comes in.
You can read more about WPA at Baseball-Reference.com. But in short, think of it as getting points for doing something good (e.g. home run) and losing points for doing something bad (e.g. strikeout). And the player gets more points or loses more points if the at bat comes at a time that will have a bigger impact on whether the team will win or lose the game.
We can then add up those points and see who has had the biggest impact in the first half, both positive and negative…
Matt Joyce has been the most important bat so far this season. According to WPA, his bat has contributed 1.58 wins in the first half. At the other end, we see Jose Molina and Will Rhymes have both cost the Rays about one win based on their bats.
Obviously some guys get more opportunities than others, so let’s scale these values per 100 plate appearances…
Now we see that Evan Longoria’s (no surprise) plate appearances tend to have the biggest impact. And at the other end, both Will Rhymes and Hideki Matsui (again, no surprise) have sucked.
Remember, WPA adds up all the positive and negative plate appearances. So let’s separate those and look at each players positive and negative contributions…
So while Carlos Pena has the second highest WPA, we also see that he has produced the most positive and the most negative results. That is, his good at bats have been worth 7.68 wins, but his bad at bats have cost the Rays nearly seven wins. So his net production has been just 1.02 wins.
Pena truly is a hot and cold hitter. And this shows us just how important Pena is to the success of the team. When he is hot, he truly can carry a team by himself. The key is minimizing the cold, and that hasn’t happened very much this season.
* Clutch is a bit of a controversy that many authors have proven to not exist. My own thoughts are that clutch is real, but that it is different from what most people consider “clutch.” I don’t think players get better in the clutch. But I do think there are players that are better at maintaining their normal ability. That is, some players get nervous in the clutch and suck. The players that are able to remain calm don’t get better, but it seems that way because other players don’t remain calm. Think of it like giving a speech in public. Some people get scared and can’t talk normally. Those that don’t get scared don’t talk better in public. But they are able to talk normal. To me, that is clutch.
All data via Fangraphs.com