The winner of the Flat Bat Award for 2016 is Cesar Hernandez of the Philadelphia Phillies. Let’s walk through his run value calculation to give you a better idea of how this number is calculated.
First is the calculation for the bunt-for-hit attempts component. Over the last three seasons, a successful bunt hit increased a team’s run expectancy by 0.439 runs and a failed bunt-for-hit attempt cost teams an average of 0.206 runs. Hernandez had 15 successful and 6 failed bunt-for-hit attempts. Thus, his run value for this component is (15 * 0.439) - (6 * 0.206) = 5.349.
The sacrifice component of the run value for bunts is more complicated. Over the last three seasons, even a successful sacrifice bunt attempt cost teams an average of 0.171 runs. However, it does not make sense to penalize players for successfully sacrificing themselves as they did exactly what their managers asked them to do. Instead, we measure a player’s effectiveness with sacrifice attempts with a plus/minus approach.
Since 2013, players have been successful on their sacrifice attempts 68 percent of the time. The difference in run expectancy between a successful sacrifice attempt (-0.171 runs) and an unsuccessful attempt (-0.343 runs) is 0.172 runs. Therefore, to compare each player’s ability to successful sacrifice himself to an average bunter, we add (1 - 0.68) * 0.172 = 0.055 runs every time he successfully sacrifices himself and subtract 0.68 * 0.172 = 0.117 each time he fails. This way, players who succeed more than the average will create positive run expectancy and players who succeed less will create negative run expectancy. Hernandez had five successful sacrifice bunt attempts and two failed attempts giving him (5 * 0.055) - (2 * 0.117) = 0.041.
When we combine the run value for bunt-for-hit attempts (5.349) and sacrifice bunt attempts (0.041), we get the 5.39 that tops the above leaderboard. We can see that most of Hernandez’s run value comes from his bunt-for-hit attempts. In 2016, he led the league in overall number of attempts (21) and was successful 71 percent of the time.