The Benefits of Facing a Poor Defense

Common sense dictates that a hitter will be better off when he’s facing a team with a bad defense and worse off when facing a good defense, but just how big is the difference between the two for practical purposes? How good or bad does the defense have to be? And are all players affected equally? As daily league players, these are all incredibly important questions to ask ourselves, and if answered correctly, can provide us with a big edge against our FanDuel opponents.

What defenses affect

So what can a defense actually affect? It seems pretty obvious that they affect things like singles, doubles, and triples, but as a result of their affect on these things, they indirectly affect every other FanDuel-relevant stat as well.

The study

To study the effects of defense on hitting, I’m going to look at all regular season games played since 2002 and compare how hitters fare against good defense and bad defenses. To measure defense, I’m using Ultimate Zone Rating (in the form of UZR/150) with a UZR/150 above 5 qualifying as a good defense and a UZR/150 below -5 qualifying as a bad defense. This gives us about 15% of all teams on each end.

The extent of this affect

The following table shows the difference between facing a bad defense over a good one (a positive number means that this stat will increase when facing the bad defense).

+----------------------------------------------------------+
| 1B  | 2B  | 3B   | HR  | BB  | SB   | RBI  | R    | OUTS |
+----------------------------------------------------------+
| +8% | +9% | +28% | -4% | -1% | +20% | +11% | +11% |  +1% |
+----------------------------------------------------------+

Naturally, we see pretty large benefits to singles, doubles, and triples. We also see big gains for RBIs and Runs, which come as a result of getting more hits and reaching base more often. Steals also flow from the increase in singles and doubles because it puts the hitter on base and in position to steal more frequently.

The hardest ones to explain are the (albeit small) decreases in home runs and walks. My guess here would be that a hitter recognizes when he is facing a bad defense and is less selective at the plate, so he walks less frequently. Similarly, if he knows that the defense is bad, he’ll be more content to merely put the ball in play instead of swinging for the fences, whereas facing a very good defense he may try to get more power behind his swing.

But it doesn’t affect everyone the same…

We could stop here, and that was the initial plan when I began writing this article, but after seeing the results, I realized something that I was missing: not all players will be affected by this in the same way! If a hitter doesn’t hit many home runs, that -4% mark isn’t going to matter, which, in turn, will have a trickle-down effect on RBIs and Runs. Also, because he’s not hitting home runs, his value is going to have come in the form of extra singles, doubles, and triples, so the effects will be magnified because his raw number of singles, doubles, and triples will be higher than they will be for an extreme power hitter.

To study my theory, I took the same approach as before but focused only on hitters who posted an AB/HR over 120 (which roughly translates to 5 HRs or less over a full season). Here are the new results:

+----------------------------------------------------------+
| 1B  | 2B  | 3B   | HR  | BB  | SB   | RBI  | R    | OUTS |
+----------------------------------------------------------+
| +8% | +1% | +28% | -5% | -2% | +26% | +20% | +13% |  +1% |
+----------------------------------------------------------+

To compare, here are the results for players with an AB/HR under 15 (which roughly translates to 40 HRs or more over a full season).

+----------------------------------------------------------+
| 1B  | 2B  | 3B   | HR  | BB  | SB   | RBI  | R    | OUTS |
+----------------------------------------------------------+
| +7% | +9% | +14% | -5% | +1% | +29% |  +3% |  +2% |  -2% |
+----------------------------------------------------------+

As we’d expect, RBIs and runs both see a large increase for low-power players while they are barely raised at all for high-power players. Because high-power players rely on home runs for their RBIs and runs, when home runs decrease, the RBIs and runs follow suit.

To really illustrate how strong these effects are, I thought it would be best to use two real-life examples from the two opposite ends of the spectrum: Adam Dunn and Juan Pierre.

Here is what happens when we apply these figures to the 2010 seasons for Dunn and Pierre:

+-------------+------------+-------+
| PLAYER      | POINTS/DAY | $/DAY |
+-------------+------------+-------+
| Adam Dunn   |      +0.08 | +$ 32 |
| Juan Pierre |      +0.46 | +$199 |
+-------------+------------+-------+

For an extreme power player like Dunn, there is very little benefit to facing a good defense over a bad one. For an extreme no-power player like Pierre, however, there is a huge benefit. In FanDuel’s MLB Salary Cap 35k format, Pierre will score 0.46 points more when facing a bad defense over a good one. Based on some rough calculations of mine, that translates into a nearly $200 difference in value for Pierre when facing a poor defense over a good one. Of course, because the price you’ll have to pay for Pierre is based off a neutral-defense expectation, he’ll be worth about $100 more than his actual price when he’s playing against a poor defense. That’s extremely significant.

Caveat

Detracting from this a little is that my studies were conducted knowing who the good and bad defenses were. At the start of a season, we can’t be sure which defense are good and which are bad, though we do have some idea.

Suggested FanDuel picks

This exercise tells us that when we’re selecting our FanDuel players, we can essentially ignore defense when selecting a power hitter. When contemplating a non-power hitter, however, we need to pay heed to the defense the player will be up against. If you’re playing in tomorrow’s Saturday Home Run contest, for example, an interesting play might be Cubs speedster Starlin Castro against the Pirates, who figure to have a pretty poor defense this season. You’ll probably want to avoid Cardinals leadoff hitter Ryan Theriot (and #9 hitter Skip Schumaker), though, since he’ll be facing a pretty good Padres defense. But feel free to pick Albert Pujols since the Pads defense won’t have much impact on his overall production.

Concluding thoughts

If anyone has any questions, as always, feel free to comment or e-mail me. Also, be sure to add me as a friend on Facebook and follow me on Twitter.

Derek Carty’s work can also be found at The Hardball Times Fantasy and DerekCarty.com. He has previously had his work published by NBC’s Rotoworld, Sports Illustrated, FOX Sports, and USA Today. He is the youngest champion in the history of LABR, the longest-running experts league in existence, and is a graduate of the MLB Scouting Bureau’s Scout Development Program (aka Scout School). He welcomes questions via e-mail, Facebook, or Twitter.

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