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The Arizona Diamondbacks W-L record lags expected win totals from Pythagorean and WAR estimates

The Diamondbacks expected win totals outperform their current season record

MLB: New York Yankees at Arizona Diamondbacks Mark J. Rebilas-USA TODAY Sports

One of the story lines from the beginning of the season is the Diamondbacks having a disappointing start to the season. Through 46 games, the team is 21-25 and has been very streaky of late. The biggest factor towards that has been the guys that were expected to carry the team in 2016 have been unable to and it's been the unexpected contributors that have carried the team. Even though the Diamondbacks are 4 games below .500 and 6 games back of the NL West leading San Francisco Giants, there is still hope for a quick turnaround in late May-early June, similar to the 2011 team that wound up winning 94 games and was near impossible to beat in the 2nd half of the season.

Most teams that lose an All-Star days before the season start, have their best player endure the worst slump of his career, their marquee FA signing and big ticket trade acquisition struggle mightily, and another All-Star caliber player have to spend time on the DL for wrist issues, you would have thought the team was ready to give up on the season. Fortunately, that's not the case from the Diamondbacks. As I said above, the team is finding help from unexpected sources, especially if you watched the team from 2015. Who are these unexpected contributors? They are Jean Segura, Chris Owings, Yasmany Tomas, Chris Herrmann, and Rubby De La Rosa. In addition to those unexpected contributors, we've seen drastic improvements from Jake Lamb and Brandon Drury at the plate after down seasons in 2015.


The Diamondbacks have scored 214 runs and have allowed 218 runs on the season. Using the Pythagorean formula, the Diamondbacks expected winning percentage should be .492 and expected win total of 22.6. That would make the Diamondbacks a 23-23 team. If you extrapolate this through a 162-game season, that gives the team a projected 80-82 record. Obviously no one reading this article would be happy that the Diamondbacks spent so much baseball capital just to improve by one game.


The Diamondbacks have 10.4 fWAR (Fangraphs) and 10.1 bWAR (Baseball Reference). Both Fangraphs and Baseball Reference have standardized the winning percentage of a replacement level team to be around .294. If you do the math and multiply the .294 mark with the team's 46 games played then add the WAR total, the team's expected win total is 24 (23.6 via bWAR, 23.9 via fWAR and both round up to 24 wins). That's one win above their Pythagorean expectation and 3 wins above their current win total for the season. If you extrapolate this to a 162-game season, then the Diamondbacks are expected to go 84-78, which will also not get the job done.

For those wondering, I've compiled a nice spreadsheet for the team's war totals. I've taken the average of fWAR and bWAR since the two website have completely different formulas in their WAR calculations, especially when it comes to pitchers.


The Diamondbacks are under-performing their Pythagorean total by 2 games and their WAR totals by 3 games. Looking at one-run games, the Diamondbacks are 3-5 on the season and have been outscored 29-31 in those games. In that area, the Diamondbacks are 1 game below the Pythagorean number, which asymptotically approaches .500. Another area where the projection seems to be off is the Giants series in Chase Field, in which the Giants swept the Diamondbacks by the strength of a 14-7 overall series score. It's the case of the Diamondbacks being unable to win in close games, where the 2-game difference shows up. The Diamondbacks are 14-20 in those games, although the Pythagorean expectation would be 16-18 based on a -10 run differential in those games.

One thing I do know is the season is still very young and barely just past the quarter mark. To put it in baseball terms, the season is in the bottom of the 3rd inning and they're down a couple runs. The Diamondbacks have played better than their W-L record suggests, perhaps the close game luck will swing the other way and the Diamondbacks start winning those games more frequently. The Diamondbacks are 14-8 on the road and 7-17 at home. Perhaps some of the road success can finally carry over to when the team comes home on Friday. They did sweep a Cardinals team that was above .500 in their own ballpark, so maybe that's the first step towards contention. In the immediate future, they're going to have to prove themselves against a very good Pittsburgh team that took 2/3 from the Diamondbacks at Chase Field.