# Bases Earned per Innings Pitched

Updated: Dec 23, 2018

*A New Statistic to Analyze Pitcher Performance*

*\ Written by Caleb Whittemore \ Published July 17th, 2018 \*

If you find yourself watching an MLB broadcast, I guarantee you have heard the broadcasters talk about a pitcher’s Earned Run Average (ERA) in reference to their performance. Earned run average essentially calculates how many runs a pitcher is “responsible” for on average, over 9 innings pitched.

There are some flaws in this statistic. For example, if the shortstop bobbles the ball on a grounder and the baserunner is safe at first, the play will likely be ruled an error. If the pitcher then gives up two base hits and the first runner scores, the run is not charged to him in any way because the error let him on, even though the pitcher’s performance allowed 3 of the 4 bases. If a reliever comes in with the bases loaded and two outs and then proceeds to give up a base clearing double, the pitcher who allowed the runners is still responsible, even though he hypothetically could have struck out the final batter before he left in the game. People in baseball argue that this is something high-end relievers like Craig Kimbrel get away with. He is dominant in clean innings but struggles when runners are already on. When he allows inherited runners to score there is no consequence to his ERA.

There are some advanced metrics that paint this picture a little better, but nothing thatin my opinion is comprehensive and easily understandable for casual fans. Baseball needs a new metric that is similar to ERA yet gives a more accurate analysis of a pitcher’s performance.

Because of this problem, I set out to find an accurate depiction of pitcher performance that can be understood by all types of baseball fans. While looking at ways to address this, I created what I call “Bases Earned per Innings Pitched”. This is a single metric that is easy to understand and divides fault, or credit, more evenly for the previously referenced issues.

To calculate this statistic, you would need to track each base a pitcher allows and divide it by his total number of innings pitched. A single would be 1, a double 2, triple 3, and a homerun 4, as well as adding in all the bases advanced by a runner because of an event the pitcher allowed. In the previous example, the shortstop made an error that allowed a runner on, so the pitcher would not earn a base. However, if the next player hits a home run, the pitcher will have allowed 7 bases (4 for the hitter and 3 from the baserunner). Or if a pitcher enters the game with the bases loaded and gives up a base clearing double, he won’t be charged with the bases earned before he entered the game, but he will be charged for allowing the hit that drove them in, 8 total bases (2 for the batter who hit the double, 3 for the runner who scored from first, 2 for the runner who scored from second, and one for the runner who scored from third.)

There are obviously a lot of other outcomes in baseball that I have not covered. Here are a few of the common ones and how they would be scored:

- Single: 1 base, plus a base for every base any additional runners advanced.

- Double: 2 bases, plus a base for every base any additional runners advanced.

- Triple: 3 bases, plus a base for every base any additional runners advanced.

- Home Run: 4 bases, plus a base for every base any additional runners advanced.

- Base on Balls: A base for the batter plus a base for every additional runner that advanced.

- Balk: A base for each runner that advanced.

- Passed Ball: No bases allowed (passed balls are the fault of the catcher).

- Wild Pitch: A base for every base any runners advanced.

- Base Hit, with an error on an additional throw: Bases given as a result of the original play, any extra bases because of an error in the field will not count.

- Sacrifice Fly/ Bunt: Any bases the runners advanced on will be charged. This gives incentives not to give up deep fly balls with runners on.

The great thing about baseball metrics is they can always be improved. No one statistic, not even WAR, can show the complete value of a player. We must always try to find ways to improve metrics, and letting ERA continue to be used as the mainstream pitch statistic just because it is status quo is a shame. Having said that, it is important for whatever takes its place to be something to which the casual fan can easily adapt. I think “Bases Earned per Inning Pitched” accomplishes that. It tells the story in a similar way as ERA, but it goes about it in a way that is far more accurate.

*Image by *__SI.com__