The Arizona Diamondbacks defeated the Milwaukee Brewers last night. Arizona maintained their 3 1/2 game lead in the west while knocking the Brewers out of first place as the Cubs defeated the Giants. It was the 28th one-run win for the DBacks. Jeff Protzel writes (during last night’s game):
I was wondering if you’d devote an entry to the AZ Diamondbacks. For the life of me, I can’t figure out, short of being in a very mediocre division, how they have a winning percentage of .559. Their Pythagorean projection would put them at .471. So they are playing 11 games better than they should based on RS/RA. They have noone on the offensive side of the ball with an OPS higher than .900, and they are 13th out of 16 teams in runs scored and OPS. As for pitching, except for Webb their starters are decidedly mediocre (not another starter with lower than a 1.40 WHIP). They are, however, 6th in the NL in ERA. How are they doing this? Perhaps its their 27-16 record in 1-run games? I think this would be an interesting discussion if you haven’t tackled this topic yet.
The one-run game record has a lot to do with it, but to drive the point home, here’s a graph of the distribution of score differences for Arizona this season (click for a larger image). Positive difference are wins, negative losses.
Notice that the Diamondbacks not only win one-run games, but they have a winning record in two, three and four run games as well. The Arizona Diamondbacks are why we figure medians. Their mean run difference this season is -0.2422. In other words, they lose on average by a quarter of a run. But if you look at the distribution, there are a large number of outliers at the negative end of the distribution. So this is a case where the median might be a better measure of the team’s run scoring, and sure enough, the median run difference is one.
As for the pitchers, while it’s true that Webb is the only great starter, they do have a number of oustanding relievers. So the mediorce starter only gets to perform for six innings. Let’s say you use a starter with an ERA of 4.50 for six innings, and a set of relievers with an ERA of 3.00 for three innings. That’s an ERA of 4.00 for the game, and most teams can win decently with that. Throw in Webb for 32 starts the team wins a good number of games. With a little luck, that’s enough to send you to the playoffs.
The author is correct, the Diamondbacks are due a 10-12 game losing streak. I wouldn’t at all be surprised if that started this weekend against the Cubs, who are still playing below their Pythag %.
Just a passing comment, because I keep hearing references to the NL West being very weak, and thus — the conclusion being whatever, such as, that’s why Arizona has the record it does.
The analysis shouldn’t end with this, but it should start with the NL West’s record against the rest of the NL: vs. the East: 81-64; vs. the Central: 90-83.
My own seat of the pants analysis is that the best team in the NL West is usually weaker than the besy of the other divisions, but that the 2-4th are generally stronger than the comparable teams in other divisions. This year, though, my seat of the pants analysis is that the whole league is bad.
But the reason AZ is atop its division: the NL East. AZ’s record against the NL West: 24-23; against the NL Central: 16-17; against the AL: 8-7. Against the NL East? 24-9.
Any team with a winning record has a median run differential of +1 or greater by definition. The median run differential may show something about the quality of the teams, but I can’t see how it is evidence of superior performance for the D-Backs, since it is the minimum possible for a winning team.
I find it hard to believe that the west in considered weak, just look at the stats:
vs East vs Central vs West
East 117-117 .500 99-75 .569 64-83 .435
Central 60-81 .426 131-132 .498 69-78 .469
West 83-64 .565 91-84 .520 118-118 .500
Even if you take out AZ stats against the East, the West still has a .517 W-L percentage against that division, still the best W-L % in the NL. In addition, the best team in the East, the Mets, have a losing record, 15-17, to the West.
However, I concur that the NL is the weaker division:
vs INTR
East 38-43 .469
Central 35-46 .432
West 34-44 .436
Here are the combined W-L stats for each division, again, the West comes out on top.
Totals
East 318-318 .500
Central 295-337 .467
West 326-310 .513
Throw in the fact that the West has some of the most dominating pitching in the league: B. Webb (AZ), J. Peavy (SD), C. Young (SD), B. Penny(LA), B.Zito (SF) in addition to SD and LA leading the league in pitching, #1 at 3.54 and #2 at 3.99 respectively, with the D-Backs not far off the pace, #6 at 4.09, and you have one of the toughest divisions in the NL.
The D’backs are currently tied for 40th ALL-TIME in Win % in games decided by 4 runs or less. That’s out of nearly 2,200 teams. Even more impressive, they are tied for 13th in the expansion era (1961 on), out of 1,200+ teams. Only 5 teams have a better record in close games in this millenium, and they all won over 100 games!
Az has a chance to tie or perhaps even break the ALL-TIME record for biggest difference between actual and pythagorean wins. Winning the close ones is obviously very important, but getting blown out occasionally is even more critical to their success. Too bad that 30-3 loss belongs to someone else!