Projo Fantasy Sports Blog

By Michael Salfino

Last week, some readers responded to my Justin Duchscherer "sell" and projection for a regression to average luck in having opposing balls in play (BIP) converted into outs by noting that his park, McAfee Stadium, seems to generally favor pitchers in this regard.

How can a ballpark have a bias in favor of converting BIP into outs? Yes, McAfee does have generous foul territory. And since any fielded batted ball, whether fair or foul, counts, this extra room in which to catch foul pops helps. But we're talking about a small number of plays here.

In 2007, more foul pops were caught in Oakland than anywhere else: 4.2 percent of BIP. The league average was 2.9 percent. So the impact of the extra foul territory on BIP average there seems small, about three points in '07.

This year, the A's pitchers allow a .259 average on balls in play at home, .293 on the road (average is usually about .300). Last year, home and away, it was .283 and .314. In '06, .299 and .307. And in '05, .269 and .277. I went back 10 years and the pattern holds every time.

Maybe what we're seeing is a classic home/road bias. In other words, players in all sports tend to perform better at home than on the road. If McAfee truly suppresses BIP, A's hitters should also do worse at home than on the road.

This year A's hitters are .288 on balls in play at home, .307 on the road. Prior years also favor A's hitters on the road, but more mildly. But in 2005, A's hitters actually had a higher BABIP at home (.286) than on the road (.277).

Some have speculated the reasons for this park factor are a crummy batter's eye in center, a slower-than-average infield (higher grass) and the generally colder air off the bay (colder air is more dense than warmer air and thus harder for a batted ball to travel through).

Of course, we don't have to explain it for it to be true. It is safe to assume that A's pitchers benefit from this park factor when at home. Keep in mind, Justin Duchscherer owners, that he's on the trading block, so that home cooking going forward might not be as nourishing to his stats.

Let's quickly look at some other park factors.

Scoring is up more than 20 percent this year at fields Wrigley (Cubs), Turner (Braves), Chase (Diamondbacks) and Coors (Rockies). It's down 24 percent at Dodger Stadium and more than 15 percent at Tropicana Field (Rays), PNC Park (Pirates) and Petco Park (Padres). Petco, by the way, has a similar effect as McAfee on BIP.

Homers are up 54 percent at Camden Yards (Orioles), 47 percent at U.S. Cellular (White Sox), 36 percent at Coors and 29 percent at Rangers Ballpark. They're also up 10 percent at McAfee, so Duchscherer's success at limiting homers (as a percentage of fly balls hit) remains unexplained and is likely to correct regardless of whether he's traded.

Homers are down more than 30 percent at Tropicana and Progressive Field (Indians); more than 20 percent at Dodger Stadium and PNC Park.

Some of these tendencies need to be tracked against prior years. For example, Rangers Ballpark was neutral for homers last year but favorable most others. All the other parks cited consistently favor hitters or pitchers as suggested by this year's stats, though obviously not to that precise degree.

So, generally, you want to buy hitters and sell pitchers in the hitter's parks above and vice versa with the pitcher's parks. Here's where you should start.

Buy

Alfonso Soriano, OF, Cubs: Hand injuries are always tricky for power hitters, but Soriano reported no lingering pain during his rehab stint, which ends this week. He had 15 homers in about 200 at-bats before getting hurt and will find the warm Wrigley air very inviting through August.

Paul Maholm, P, Pirates: Pitching in a park that suppresses runs and homers is a reason to double down on a pitcher. But they're tough to find in Pittsburgh. Maholm is the only one I can recommend, given his OK stuff (5.9 Ks/9) and excellent control (2.2 BBs/9).

Hold

B.J. Upton, OF, Rays: Striking out a ton, still, but now walking a ton, too. The homers are going to come; I'm convinced there's lightning in those wrists. And the bags (30) are a huge bonus.

Sell

Randy Wolf, P, Astros: Goes from a park that cuts scoring nearly 20 percent to one that boosts it more than 10 percent. Note the 6.63 road E.R.A. for Wolf (he had a 3.17 rate at Petco).

Rich Harden, P, Cubs: You can get top dollar now after his auspicious NL debut. But the change in park environment could hardly be worse and he throws so hard that he defies the physics of his rather slight anatomy. This makes yet another injury more likely.

Carl Crawford, OF, Rays: What a bust this year. Isn't running enough (23 bags) and the average has hit the skids, which makes sense when you look at his always poor plate discipline. His park, of course, doesn't help.

 Tags  Alfonso Soriano B.J. Upton Baseball Baseball by the Numbers Carl Crawford Michael Salfino Paul Maholm Randy Wolf Rich Harden

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