In today’s analysis of baseball, the term WAR — wins above replacement — has become almost as ubiquitous as canonical statistics like strikeouts, walks and home runs. Essentially, WAR is a metric that attempts to quantify how valuable a particular player is.
WAR measures how many more wins a team gains by using player “A” rather than a “replacement level” player. Replacement level refers to the quantifiable skill of a bench player who might fill in for a starter in the event of injury. Typically, replacement level is considered to be below the league average for a given player, and in terms of the Ivy League, one can think of Division III as the replacement level.
I first took interest in WAR for Ivy League baseball and softball last year, and now that a sufficient number of games have been played, I turn to numbers to reveal this year’s Ancient Eight softball MVPs.
There are two types of Ivy WAR that I maintain — a player’s value as a batter, called offensive WAR — oWAR — and the player’s value as a pitcher, called pitching WAR — pWAR. The two main components used to calculate oWAR are “Batting Runs” and “Base-running Runs.” The number of runs a player produces while batting is computed by applying various weights to traditional statistics, including hits, walks, home runs and runs batted in. The logic behind these weights is that a double is more valuable than a single, but perhaps not twice as valuable. Next, players are penalized for every double play they ground into, as they cost their team an additional at bat by creating an extra out.
To account for the value a player adds on the basepaths, I credit players for stolen bases and penalize them each time they are caught stealing. To translate runs created above replacement into oWAR, I divide by the “Runs Per Win” constant. In Ivy League softball, the ability to create roughly eight wins above replacement translates into a win.
Pitching WAR is computed in a similar way. It is driven largely by a statistic called Fielding Independent Pitching, a measure of pitcher skill based only on the outcomes she can control: strikeouts, walks and home runs.
Harvard shortstop Rhianna Rich leads all Ancient Eight batters with oWAR of 2.24. This is no surprise given that the Crimson junior finished her sophomore campaign as the second-most valuable offensive player in the conference, in which Rich was worth 2.5 oWAR.
Yale’s most valuable offensive threat, and the third most valuable batter in the Ivy League, is outfielder Shelby Kennedy ’19. Kennedy’s oWAR of 2.04 gives her a great chance to surpass the 2.15 oWAR she contributed last season, good for fourth in the league. WAR is a good statistic for capturing Kennedy’s value, as she has yet to hit a home run and has driven in only three runs all season, but remains an integral part of the Eli offense despite what traditional statistics might suggest. Breaking her oWAR down into its distinct components reveals that Kennedy is best in the Ancient Eight at creating value on the basepaths. She has an elite on-base percentage and has stolen at least 10 more bases than all but one player in the conference.
Another Bulldog, Terra Jerpbak ’18, has been the most valuable pitcher in the league, with a pWAR of 3.46. Despite a 3–6 record on the mound, Jerpbak has pitched much better than her record might indicate. She has struck out more batters than any Ancient Eight pitcher, has given up fewer than any hurler to have tossed at least 45 innings, and of the hits she has allowed, the majority were limited to singles. Thus, her league-best FIP suggests that her underwhelming win percentage could be due at least partly to bad luck. The only thing preventing Jerpbak from being the most valuable all-around player in the Ivy League is her oWAR of -0.11, yielding an overall WAR of 3.35.
Harvard junior Kathleen Duncan has been the most valuable player overall this season, providing the first-place Crimson with a 3.40 pWAR and a 0.45 oWAR for a net total of 3.85 wins above replacement.
Traditional measures of WAR would also include a defensive, or fielding, component, though the data that exists at the college level is not granular enough for estimating such a contribution. As a result, this method of player evaluation will inherently undervalue players whose strongest “tool” is their glove, rather than their bat or their arm. That being said, oWAR and pWAR provide strong grounds on which to evaluate Ivy League softball players and reveal the key cogs to both Yale and Harvard’s success this season.
Luke Benz is the President of the Yale Undergraduate Sports Analytics Group.
Luke Benz | firstname.lastname@example.org