Last week we took a look at how the wind and his home park affected Kevin Youkilis‘ home-run production in 2008. Youkilis is an example of a player who is being overrated due to some homers receiving a boost from those factors, but it can work both ways; there are also players who are underrated due to these same effects holding their power numbers down, and this time out we’ll take a look at one of them.

Adrian Gonzalez has quietly been one of the better hitters in the game the past few seasons as he toils away in the pitcher’s heaven of Petco Park. Last year he compiled 45.8 VORP, his second year in a row with at least four wins above replacement level with his bat, by hitting .279/.361/.510. While that line may not seem like very much without any adjustments-his OPS of 871 tied him for 40th among qualified hitters-it’s far more impressive once you take his playing in Petco into account. His equivalent line of .298/.378/.554 is much more eye-catching, and were it his actual rather than his adjusted line, he would have ranked 13th on the OPS leader boards.

I’m not using OPS as a gauge of how valuable Gonzalez actually is, but it is interesting to see how much of an improvement there is in his line simply by taking Petco out of the equation. His .311 EqA last year suggests that he was one of the 10 best hitters in the National League, but if you were to ask someone to compile a quick list of just who those players are, chances are he’d be skipped over-you simply don’t hear his name mentioned along with those of Albert Pujols, Chipper Jones, Hanley Ramirez, David Wright, Lance Berkman, or Matt Holliday very often (though teammate Brian Giles, in his quest to be perpetually underrated while also toiling in Petco, actually ranked ahead of Gonzalez last year in EqA thanks to his fantastic walk rates and decent power).

Let’s take a look at the difference between Gonzalez’ performance at home and on the road during his three years as a Padre:

           Home                      Road
Year   AVG/ OBP/ SLG   ISO       AVG/ OBP/ SLG   ISO
2006  .296/.344/.471  .175      .311/.378/.527  .216
2007  .266/.335/.424  .158      .295/.358/.570  .276
2008  .247/.355/.433  .186      .308/.368/.578  .270

Total .269/.345/.442  .173      .304/.367/.560  .256

We’re talking about two completely different players here. The home line looks like something you might expect from Adrian Beltre or James Loney, while the line from away games looks like a more powerful version of Josh Hamilton, or Lance Berkman with far fewer walks. It’s well known that Petco hinders power and hitting overall, but the extremes to which it punishes Gonzalez are somewhat mind-boggling.

Let’s take a look at the specifics of Petco regarding Gonzalez’ power production, courtesy of the Hit Charts at


Gonzalez had power to all fields in 2006, but it wasn’t extreme power; his homers barely cleared the wall at Petco, and just 10 of his 24 long balls came at home. In 2007, Gonzalez failed to hit a single home run over the wall in left field, instead picking up a few doubles and loads of long, fly-ball outs. Again, 10 of his home runs came at Petco, but this time it was 10 of 30. Lastly, we have 2008, when Gonzalez seemed to realize that hitting fly balls for normal distance just wasn’t going to cut it; he hit eight homers over the wall in left, with all but one of those qualifying as deep shots for Petco. He also had a handful of warning-track shots that probably would have gone out in many other parks, as well as a few doubles along the warning track. Just 14 of his 36 home runs came at Petco, but you can see that this number should have been higher; I’m counting nine warning-track shots, and if you assume that half of those should have been home runs, then Major League Baseball should have had three 40-homer guys last season.

Looking at his complete homer data from Hit Tracker, we see that Gonzalez wasn’t very lucky with his home runs in ’08, and that he has legitimate power. He had one homer off of Alex Hinshaw on June 1 at San Francisco that would not have left any other stadium, and another off of Logan Kensing on May 3 at Florida that would have left eight of them, but 30 of his homers would have been gone in at least 22 of the 30 parks in the majors.

Hit Tracker uses two distances for home runs, “True” and “Standard.” We’re going to use Standard Distance here, for reasons you’ll understand from its glossary entry:

The estimated distance in feet the home run would have traveled if it flew uninterrupted all the way down to field level, and if the home run had been hit with no wind, in 70-degree air at sea level. Standard distance factors out the influence of wind, temperature, and altitude, and is thus the best way of comparing home runs hit under a variety of different conditions.

The average standard distance of Gonzalez’s Petco home runs was 392.4 feet, while the average standard distance of all of his other homers was 392.2 feet. There’s a large discrepancy in the rate at which he hits homers, despite hitting the ball the same adjusted distance both at home and away. As for the “True” distance, which is how far the ball actually travelled (though estimated for distance if the ball’s flight was interrupted prior to reaching field level), Gonzalez averaged 402 feet on the road, and just 390 feet at Petco. He does have Coors to contend with however, which does increase the average distance-take out the three he hit at Coors, and his True Distance average becomes 395 feet.

I’m not sure that I’m comfortable with removing Coors from the equation entirely, but even if we do, there’s a discrepancy between the average distances that’s still significant-think back to those warning-track shots that just missed. If you look at all of the home runs hit at Petco last season, we see that the average Standard distance is lower than the True distance by 1.3 feet; players actually got a tiny boost from the wind and temperature, though as you can plainly see in the overall results, the dimensions of the park override that teeny bump. Hit Tracker accounts only for the balls that actually became home runs, so it’s difficult to gauge just how adverse of an effect the dimensions have on the totals, but we can take a look at a scatter-plot to get some idea:


There aren’t a lot of balls that cross the wall and keep on going at Petco, probably because the dimensions in left and right-center field are extremely deep, while left and right field also sit far back except for in the very corners of fair territory. Now picture Gonzalez’ warning-track outs and doubles, and think about how just another five to ten feet could have converted a few of those into home runs, bringing him closer to a balanced home/road split.

It’s funny that Gonzalez was once with the Texas Rangers in a park that last year saw 2.5 home runs per game and 204 on the season. The average True Distance there is 405.1 feet, 8.8 feet further than the average Standard Distance; the temperature, wind, and altitude all transform Arlington into the American League’s version of Coors Field. If he’d not been traded along with Chris Young a few years ago, it might have been Gonzalez who was the focus of the previous piece on overrated power hitters using their home park to advantage, rather than today’s, as one of the more underrated bats in the game.

You’re not going to take Adrian Gonzalez in an earlier round in your draft because of this, but the information does provide an important lesson on how much factors like park dimensions can affect a player’s performance. Kevin Youkilis and Carlos Quentin were both lucky last year, in the sense that their home parks boosted their production considerably, but both of those players are still there in 2009, and you should use that knowledge to your advantage on draft day. Conversely, if both of them were to be traded to a team like San Diego with our friend Gonzalez, or to Oakland as Matt Holliday was this winter, it’s important not just to know by how much, but also why your expectations for them should be lowered. Knowing more about park dimensions will help you to figure out that Raul Ibanezmoving from a pitcher’s park in Seattle to a hitter’s park in Philadelphia may not be as big of a deal as you think, or on the pitching side of things, that someone like Kyle Lohse has added value due to his pitching in a place that deflates home runs, which have been his one major stumbling block as a pitcher.

You’re beginning to see new statistical terms that you never expected would enter into the mainstream lexicon, leveling the playing field and hurting those owners who were ahead of the curve just a few years ago. The same thing is happening in real baseball, as the market inefficiencies discussed in Moneyball are generally accepted now, and teams keep moving on to more advanced information (such as Pitch F/X, or video scouting) in order to find an edge. There’s no reason you can’t employ some of that on the fantasy level in order to once again move ahead of the curve.

Thank you for reading

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I can't help but feel bad for Adrian. What kind of numbers would be put up in a hitter friendly park?
"You're beginning to see new statistical terms that you never expected would enter into the mainstream lexicon."

So true, and this must be at least partially due to BP's increased presence by partnering with ESPN. My days of exploiting other owners during the draft may be over. :(
Absolutely true, drewsylvania. I've won an extremely competitive money league the last 2 years with BP and the insights I get here. Last year I had the 14-team locked up a full month before the season ended, and ended up with 128 out of a possible 140 points! My draft this year tells me I still may be ahead of the curve, though. Hopefully I'll get one more year.
"We're talking about two completely different players here. The home line looks like something you might expect from Adrian Beltre or James Loney"

I'd just like to point out that you could have written the same article, more or less, about a totally different Adrian, namely Adrian Beltre. He's not quite as good as Gonzales with the bat, but his H/R split is similarly extreme.
I feel like Boston should be doing whatever it takes to get this guy off the Padres. He'd mash in that ballpark, he'd be cheap, he'd fill the gap at first base and they have plenty of prospects to offer the Pads in exchange. If he's one of the top hitters in baseball outside of Petco, having him at Fenway would be a pretty good counter to losing out on Texeria. Just a thought.

That was exactly my thought, too. When does Gonzalez stop being under team control?
I believe that Red Sox will pry him away from the Padres. With Kyle Blanks, a dwindling payroll, and a barren farm system, Sandy Alderson (or whomever is calling the shots now), should move Gonzalez and Peavy to the Sox for Lars Anderson, Clay Buchholz, Josh Reddick, and Justin Masterson.
I'm not sure I would do that deal, as a Red Sox fan. But only because I want to see Anderson and Reddick blossom in Boston. Well, that and I keep wondering if Peavy is going to fall apart.
@keeperleaguegm--from your mouth to god's ears! as a buchholz owner, man would i love to see him get an everyday rotation slot in petco.

on another note, i wonder if, when and if peavy moves on, they'll finally move the fences in there to build a team around gonzalez's power (assuming he hasn't moved on by then too).
I loved this pair of columns, thanks again.
As a Mariners fan, I feel sorry to Beltre for his 30 homerun power being punished by the right-handed-batters' hell named Safeco. If he could just move to another team, he would have been a bona fide allstar.
there are some that say Beltre was never a star just a one year fluke who got rewarded very nicely
Yah, and if all his years were 'walk years' he also would be a bonafide All Star, too...
Fun to read, but the hypothesized Petco dimensional anomalies within this essay remain far from empirically proven. Other analysts have speculated that what is really at work at Petco, like at other salt-water adjacent open stadiums, are normal seasonal weather patterns (wind, temperature, and relative humidity) that matter far more than +/- 10 feet of stadium wall-to-plate distance. Break down Gonzalez' performance month by month and you will get an idea of what you might have overlooked. In any case, since the Petco dimensional effect remains a hypothesis, this is good news, since the 'effect' eventually will be affirmed or disproved, and we can all move. But get ready for the inevitable, similar, overreaching dimensional analyses regarding the Mets new Citi field.
As for the comments regarding Gonzalez and the RedSox, these are amusing, and expected, over-the-top examples of the oft-mercenary natures of RedSox fans who expect the baseball world to revolve around the whims of those who inhabit the chilly fens of Boston.
as a new yorker, i feel obliged to say, about the above: oh, snap!
As a Red Sox fan, I must say, we will stop feeling that way when we stop being perennial World Series winners/contenders with a top minor league system to boot. To the victor go the spoils, our team is run really really well. In Theo we trust.
Thanks very much Marc for the insights! I for one like to see this kind of article that really digs into data. Over the last couple of years I have come to miss some of your talented contributors who have been poached by various baseball organizations to work for them and keep their insights and methods private and for themselves. Dan Fox comes to mind.

Keep up the good work.
We wished Mr. Lucchino and his other San Diego acolytes, including Theo, the absolute very, very, best when they left for the Fens years ago. They certainly have proven how astute WestCoast baseball minds can win a World Championship (even) in Boston? But here in SanDiego it will be a new and different ballgame now with Moorad at the helm :)
Good post. It'll be interesting to see if Adrian's power numbers develop as he adds a bit of strength during his peak years.