Random Fandom

One complaint this season is that the D-Backs couldn't hit the broad side of the barn if said barn was playing first base or was perhaps the cutoff barn.

I wanted to take a look at the available defensive statistics to see if there was any truth to the allegation. Now, I realize that defensive metrics -- at least the publicly available -- are highly suspect. See this discussion from Baseball Prospectus for the basics. But I'll do the best I can with what I got. (Which may not be much.)

First, traditional statistics -- NL teams ranked by number of errors:

mon 21
chc 22
lad 26
fla 27
col 27
hou 28
stl 30
mil 31
sfg 34
phi 35
sdp 37
pit 37
az 38
cin 39
nym 45
atl 47

Obviously, the fact the Diamondbacks rank 13th on this list is not good. Ranking by fielding percentage makes Arizona look slightly better, though not by much.

chc 22 .989
mon 21 .989
fla 27 .987
lad 26 .987
col 27 .986
hou 28 .986
stl 30 .985
mil 31 .984
sfg 34 .983
phi 35 .982
az 38 .981
sdp 37 .981
cin 39 .981
pit 37 .980
atl 47 .977
nym 45 .977

So the Diamondbacks fare slightly better, moving up to 11th. Now, it should be noted that the difference between the Mets and the Cubs/Expos is roughly 18 errors (assuming about 1,500 defensive opportunities thus far), or about 1 error every 3 games. This is not a terribly significant difference, especially around the middle of the pack.

How about Defensive Efficiency? MLB provides this stat, as does Baseball Prospectus -- for what appears to be the first time, BP accounts this year for reaching by error, which seems to be a valid correction to MLB's stat. Here are both stats, and the table ranked by BP's stat.

stl 30 .985 .7320 .7213
fla 27 .987 .7260 .7170
lad 26 .987 .7240 .7159
nym 45 .977 .7310 .7120
mon 21 .989 .7220 .7117
chc 22 .989 .7180 .7079
hou 28 .986 .7180 .7044
mil 31 .984 .7150 .7000
phi 35 .982 .7130 .7000
cin 39 .981 .7100 .6968
sfg 34 .983 .7080 .6967
az 38 .981 .7090 .6935
sdp 37 .981 .7070 .6908
col 27 .986 .6920 .6848
atl 47 .977 .7030 .6817
pit 37 .980 .6930 .6771

In this case, Arizona slides back down a notch to 12th place. Differences in the middle of the pack are still somewhat small (maybe 9-10 outs for the season so far between the D-Backs and the Brewers and Phillies), though the outliers are more separated -- perhaps 66 outs turned into baserunners by the Pirates as compared to the Cardinals -- more than 1 per game.

Finally, the table below ranks NL teams by the number of unearned runs given up. This is useful mostly just to show that the "unearned run" doesn't show much. The Cubs are apparently awesome (even though their defensive efficiency is just sorta good). But I looked it up, so I wanted you to see it...

chc 22 .989 .7180 .7079 7
hou 28 .986 .7180 .7044 11
lad 26 .987 .7240 .7159 11
col 27 .986 .6920 .6848 11
fla 27 .987 .7260 .7170 14
mon 21 .989 .7220 .7117 14
mil 31 .984 .7150 .7000 15
stl 30 .985 .7320 .7213 18
cin 39 .981 .7100 .6968 18
sfg 34 .983 .7080 .6967 21
az 38 .981 .7090 .6935 25
nym 45 .977 .7310 .7120 25
sdp 37 .981 .7070 .6908 27
atl 47 .977 .7030 .6817 30
pit 37 .980 .6930 .6771 30
phi 35 .982 .7130 .7000 32

My conclusion is that Arizona's defense, while not good, and not even average, hasn't been horrible -- they've just been not average. For those of you interested, MLB's NL defensive efficiency for the past 30 days shows the Diamondbacks slipping to 13th in DE, but with virtually (slightly higher) DE than for the season as a whole.

I also think that the difference between the D-Back defense and an "average" NL defense comes down to at most 10 baserunners thus far. Those of you with better sabermetric memories than I can calculate what that might translate into in terms of additional wins and losses -- my guess, it ain't much.