A New Perspective

So far, we've been using Batter Impact to look at individual players, especially those among the top 25 batters in the league. However, for the last week, I've been experimenting with Batter Impact as a tool to look at teams as a whole. In this post, I'll show you some of the interesting things I've discovered and share some of my predictions for the rest of the season.

I first began to look at a statistic which I'm calling Team Batter Impact, essentially the sum of the individual BIs for each player on a given team. I looked to see if there was a correlation between Team BI and Winning Percentage. A scatterplot is shown below.

There seemed to be a decent correlation between Team BI and Win Percentage for all 30 teams. A few outliers were of course present (namely the Giants, Brewers, Braves, and Cubs), but we'll get to those shortly.

6 Week Summary - Tulowitzki On Fire

Troy Tulowitzi is off to a start unlike any other player in baseball. He's posting the highest batting average (.391), OBP (.497) and slugging percentage (.750) of any player in baseball and no other batter is even close. According to FanGraphs, he also has the highest WAR in baseball with 3.6 wins above replacement, 1.3 more than the next closest challenger, Mike Trout. But what's been most impressive for me has been his astronomical batter impact.

Right now, his Batter Impact is sitting at 26.9763, a full 5 points above Giancarlo Stanton, the nextbest batter as measured by Total BI. To put that in perspective, Chris Colabello is 5 points higher than Ryan Howard in the middle of the standings. Here's the top 25 (click to enlarge):

Two Weeks In

We're only two weeks into what's going to be a long season and we've already seen some incredible things. We've witnessed a three-homer game (Ryan Braun), a grand slam by a pitcher (Madison Bumgarner), and most incredible of all, only 1 manager ejection (Rick Renteria on April 8th). The big news of the first few weeks has been, of course, the implementation of the long-sought-after instant replay system that MLB added before this season.

So far, it's working well, though with some flaws, namely that managers who use their challenge early in a game are left to hope that no call goes against them until the 7th inning. At that point, umpires control all reviews, but before the 7th inning, managers are left to make a difficult decision. Who knows if a more controversial call will come up later in the game?

Introducing Batter Impact

The idea for this blog came to me last year as I was watching a Giants game on a lazy summer afternoon. I don't quite remember the opponent, but I do remember this: sometime early in the game, Buster Posey came up with no one on base and 2 outs and singled down the middle, stopping at 1st base. The inning would end with the next batter grounding out. Later in the same game, Posey came up with 2 men on and only 1 out and smacked a single over the first basemen's head. A run scored and the Giants would rally for a couple more runs after that. As I watched Posey's heroics, I thought to myself: Posey had two hits in that game, both singles, yet they were completely different hits. One came with 2 men out and no one on and did not do much to increase the Giants' chances of scoring. Yet Posey's second hit, the RBI, not only scored a run but set up the Giants for a rally thereafter. In both plate appearances, Posey hit a single, but the circumstances in which the singles were hit were completely different. In one, Posey was gifted with an impossible task: get a rally going with 2 outs and bases empty. That is nearly impossible. In the second, Posey was sent a gift from heaven, a hitter-friendly opportunity to bring a guy home. In the second plate appearance, Posey had a more favorable situation and took advantage of it. Had he, for example, grounded into a double play instead, he would have wasted this opportunity. This all was going through my head as I watched the game.

Traditional baseball statistics, such as batting average and hits, would have treated both of Posey's hits the same way: a single. But watching Posey during that game inspired me to fashion a statistic that differentiated the two hits. I wanted to discover the impact of those hits in context. And that is what I have aimed to do with my new statistic, Batter Impact.