How many homers would Johnny Damon hit in other ballparks?


One line we’ve parroted this off-season is that Johnny Damon is more valuable to the Yankees than any other team because his plate skills align well with Yankee Stadium. With the shorter porch in right, Damon can turn what would be fly balls in other parks into home runs. Yet it’s tough to determine just how many of his home runs would have stayed in other parks. That is, until the Ballpark Overlay Tool. Using this and Hit Tracker, we can see how the same hits would have landed in other home ballparks.

The tool is quite basic. It’s a 1.2MB Photoshop file consisting of 31 layers. The first 30 represent the dimensions of each major league ballpark. The last is for our manipulation. By going to a player’s home run chart on Hit Tracker, we can paste the image onto that 31st layer, unhide the layer of the appropriate ballpark, and make our observations. So let’s look at Damon’s 2009 home runs from the perspective of Turner Field and AT&T Park, homes of the Braves and Giants, two potential Damon suitors.

Damon at Turner Field:

Damon at AT&T Park:

It looks like at least seven of Damon’s Yankee Stadium home runs would have stayed in the park at Turner, and six would have stayed in at AT&T — though there are four home runs on the borderline. So, while Damon still would have hit a healthy number of home runs at AT&T Park and Turner field, there would certainly be a drop-off, especially on the home runs towards right-center. That’s where he took the greatest advantage of Yankee Stadium.

Of course, things change from year to year, and in Damon’s case, so would the pitchers. This in no way means that Johnny will hit six or seven fewer home runs at home if he signs with the Braves or Giants. Bill Baer of Crashburn Alley explains in the comments on Capitol Avenue Club:

I think it should be noted, however (NERD ALERT!), that in using this for analysis one can’t just say, “X amount of Player’s homers in Old Ballpark would not have been homers in New Ballpark, so he should be expected to hit X less home runs.”

Albert Pujols, one of the most consistent power hitters in the game, has a standard deviation of 6 HR per season with an average of 41. That means that roughly 68% of the time, we expect Pujols to hit between 35-47 HR, and 29-53 HR 95% of the time. So, if he was moving to Seattle, we could point out that X amount of his HR wouldn’t have cleared the fence at Safeco, but he would have to have hit a lot of cheapies for it to affect our analysis of his power output.

This overlay analysis requires one to effectively chop the available sample size in half, which certainly raises the uncertainty level, especially with younger players.

The post’s author goes on to note other factors which would affect a player’s home run totals in other ballparks, including wind and fence height. There’s also the issue of long fly balls that stay inside larger ballparks but would fly out of others. I’m not so sure that makes a big difference in Damon’s case. I don’t remember him smashing balls the opposite way very often, and it’s in left-center that Yankee Stadium is at its most spacious.

Still, it’s an interesting tool that can help us better understand how a ballpark factors into a player’s performance. It leaves many questions unanswered — in addition to those above, the question of whether Damon shoots for the fence at YS remains a mystery — but I think it makes pretty clear that Damon’s power at other home ballparks just wouldn’t be the same as in Yankee Stadium. That factor, perhaps, is the leading reason for Damon’s return to the Bronx.

Glove slap to Tango for the link.

If you want to play with the tool, you’ll need either Adobe Photoshop or GIMP. You can then download the Ballpark Overlay Tool. Once you open it up, head to Hit Tracker and find a player. Right click on his home run chart and select Copy Image. Paste that into the Player layer and unhide the ballpark you want to examine. It’s a damn entertaining tool, I must say.

Update: Commenter JGS asked that I overlay Damon’s home runs over Yankee Stadium, and I’m glad he did.

Hmm…I guess there’s a reason that the Ballpark Overlay Tool is still in beta testing.

Categories : Offense


  1. JGS says:

    This is an awesome view–any chance you could put up another graphic of Damon’s home runs with Yankee Stadium overlaid so we can see where the walls are there?

  2. Eirias says:

    Edited by RAB: Holy mother of off-topic comments.

  3. JMK aka The Overshare's Excessive Back Hair Complex says:

    While it’s true that we can’t fully predict Damon’s output at different stadiums using last year’s data at YS3, it seems that Damon would probably hit around 14-20. If you look at Damon’s away splits last year (.284/.349/.446/.795), they’re eerily in line with his career numbers (.288/.355 /.439/.794). If power ages well, it stands to reason he’ll still knock out a fair amount of balls even in AT&T. Ultimately, the conclusion is right on—Yankee Stadium provides Damon his greatest value, but I doubt he’d all of the sudden only hit 8 home runs in another stadium.

    Quality post, Joe.

  4. MikeD says:

    While it’s not unreasonable that the new Yankee Stadium is responsible for Damon’s power numbers, it’s also quite possible what we’re seeing here is, ummm, noise. There’s just not much of a data sample here. Yes, Yankee Stadium was kind to lefty power hitters. It’s always been that way and I remain unconvinced that the new Stadium is any more homer happy than the old park. I generally don’t trust one years worth of data.

    Keep in mind that Damon has hit as many as 24 HRs in a season before, his first with the Yankees, and he’s hit 20 or more HRs three times in his career. The old Stadium was also a good HR park for lefties, yet Damon in 2006 hit 13 at home and 11 on the road. Not much difference. Just last year, when Damon hit 17 HRs, he only hit seven at Yankee Stadium, and 10 on the road. Taking into account that he’s a lefty with some power, and that most hitters generally hit about 10% better in their home park, it seemed reasonable to expect an increase in HRs from Damon in 2009. His road HRs came in at the lower end of his range, while his home HRs came in on the high side, and it could have been influenced by the timing of a couple of hot streaks that occured when he was home.

    Damon is a hitter who going to hit between 17 and 24 HRs as long as he’s healthy. If he returns to the Yankees, expect him to a hit a few less HRs at the Stadium, but probably a couple more on the road, for about 18-20 bombs.

    I don’t think Damon did anything different in 2009 than he’s done in the past.

    • Hughesus Cristo says:

      “It’s always been that way and I remain unconvinced that the new Stadium is any more homer happy than the old park.”


      • Salty Buggah says:

        Yea, it definitely has been more HR happy than the old park so far. In 2009, the HR rate was 1.261 in the new Stadium while it was .982 in 2008, 1.181 in 2007, and 1.023 in 2007 in the old Stadium. (Interesting note: Yankee Stadium was the 3rd most pitcher friendly stadium in 2006 with Shea being 1st and Petco being 2nd)

        But I do think it’s not as “bad” (I say that because it’s not necessarily a bad thing since we have good pitchers and a lineup of slugging ball-fuckers) as it was this year. In the beginning of the year, balls were flying but they certainly slowed down as the season progressed. So, if it stays the way it was in the 2nd half, HRs will definitely down next year.

        • themgmt says:

          The difference between 1.261 in 2009 and 1.181 is minimal when you consider lineups and pitching on both sides of the ball. Statistically, you probably wouldn’t be able to say within in an even 75% degree of confidence that the new stadium was responsible for the change based on that 1 year.

          The hit tracker and HR distances is a better indicator. Not so much the rate of HR

    • Drew says:

      I don’t think Damon did anything different in 2009 than he’s done in the past.

      Well, he did have the best offensive season of his career.

    • whozat says:

      I don’t think Damon did anything different in 2009 than he’s done in the past.

      …So? The park he played in probably turned several warning track shots into home runs. Isn’t that something that a team looking to acquire him should take into account?

      • MattG says:

        “The park he played in probably turned several warning track shots into home runs. Isn’t that something that a team looking to acquire him should take into account?”

        Not that specifically, no. They should regard Damon as a lefty with pull power and a fly ball swing, and determine if that is a good fit for their park. No team should be trying to downgrade his home run total to evaluate him. I think that’s a fool’s errand.

        Adrian Beltre is a righty pull hitter with plus raw power…but he hit 8 home runs last year with Safeco as his home park. Anyway you do the math, that’s not a good output–yet he’s a terrific fit for Fenway.

  5. Drew says:

    While these overlays are fun to play with, in its beta status it really doesn’t account for wind and all that jazz.
    How many of JD’s homers were aided by a strong RF wind? I dunno, probably a few.. ha

    It’s too late for me to look it up but I don’t remember JD being such a pull hitter in past years. He was always a slap hitter with gap power to me.

    • Salty Buggah says:

      Yea, he increased his flyballs last year (career GB/FB is .81 but last year it was .70, tied for a career low) as a result of pulling the ball. His career HR/FB is 6.3% but it was a career high 10.4% last year. Also, his career HR% is 2.2% but last year it was a career high 3.8%.

  6. Abe says:

    I believe there is a small but obvious problem with the Ballpark Overlay Tool.

    The height of the right field wall in Turner Field (and all walls there) is 8 ft. http://www.ballparks.com/baseb.....turner.htm

    The height of the right field wall in AT&T Park is 25 ft., or more than 3X as high as the right field wall in turner field. http://www.ballparks.com/baseb.....pacbel.htm

    Therefore, using a two-dimensional tool like the Ballpark Overlay Tool, one only sees how many homers a player would have hit simply based on distance. However, we all know that distance is not the only factor in determining what turns fly balls into home runs. The other is obviously height. Therefore, it is pretty clear to me, that Damon, or any other left handed pull hitter would hit more home runs in Atlanta than San Francisco if all things were equal aside from the height of the fences. I know this is a small gripe but I find it rather important.

  7. barry says:

    that overlay is of old yankee stadium I think, the walls are supposed to be a little more shallow in YS2

  8. themgmt says:

    This analysis is inaccurate. This charts his homeruns in all parks, not just NYS. Count them, 24. So though some would not go out in say Turner Field, he’s not playing 162 games in the same ball park. It’s also ignoring fly balls he hit in other ball parks that may go out in 81 games at Turner or 81 at other NL parks.

    The second conclusion about standard deviation and variance is more on point. Damon will in all likelihood hit less than 24 homeruns, but more so because he hit 17 and 12 in the years prior and typically has averaged around 17 HR since he started hitting HRs regularly.

  9. Damian says:

    What about the Gulf-Stream-like winds that allegedly send what would in other ball parks be pop-ups sailing into the second deck?

  10. crapula says:

    RAB is doing more than Scott Boras to keep Damon talk alive. If he comes back to the Yanks, I think you guys should get a cut.

    And Boras, for being a horse’s ass that the Yankees hate to begin with, should be fired.

    • Bo says:

      And Boras is a horses ass why? Because hes good at his job and gets his clients what they desire??

      • Rick says:

        I’m as big a Boras fan as the next guy but he fails more often than he succeeds. You or I could get Tex his deal or other star players. You don’t notice how many times he misses on his other clients. Example various arbitration offers he didn’t accept over recent years.

        • MattG says:

          Boras does very well for himself, because his successes improve the value of his clients as a whole, whereas his failures do not significantly impact the market. He manages his clients like a stock portfolio, valued as a whole. He does not measure success one client at a time.

          Any individual player should be cognizant of this, yet year after year a couple of his guys are always left without a chair.

    • MattG says:

      Boras should be fired?

      You mean Damon should find another agent?

  11. Bo says:

    I doubt that anyone looking into Damon would be expecting a 25-35 home run type hitter. But that doesnt mean he still cant hit and get on base and be productive.

  12. MattG says:

    I appreciate all the effort that goes into this post, but it completely ignores environmental factors. Park dimensions are not the only factor, and in fact, might be the smallest factor. Atlanta is 1,000 miles away, and it has its own climate. Balls struck in Atlanta will travel a different distance than balls struck in New York.

    All you need to do is look at park factors, from a table such as this:


    From this table, you can see that Yankee Stadium allowed 34% more home runs to right field, while Turner field allowed 14% more. So, for 2009, Damon would hit (if he played all his games in the home park) (24/1.34) X 114 home runs, or:

    20.418 home runs.

    It’s also important to note that environmental factors can change drastically from year to year. That 34% for RF might well have been due to wind patterns that will not repeat, or many other miscellaneous things. The wall IS pretty close, so it’s probably always going to tend to inflate home runs, but 34% is a lot. It’s one of the 5 or 6 most inflated home run fields in the majors, according to the chart.

    • MattG says:

      I’m sorry, this article was written in 2007. So please ignore the details, and instead just consider the concept. There has to be an up-to-date table somewhere online…

      • jack says:

        Am I missing something? You are showing the balls that WERE homeruns, right? What about the deep fly balls that might or might not have been home runs depending on the park in which he hit them. Are these “fly balls” (or what turned into doubles or triples) accounted for in this analysis?

        • MattG says:

          1.34 is a constant for home run inflation to right field. It’s the end result after you remove all the noise. It averages Brett Gardner and Mark Teixeira.

          The problem with the chart is that the marks are not in the place they would be in another park. Heck, they’re not even in the place they would be on another day in the same park. You have to remove all the noise and establish a constant.

          You would probably also want to look at the player and determine if you want to adjust the results. Some players will be more difficult to estimate by this method than others. Presumably, the more raw power the player possesses, the more reliable the park factor data would be. Although the 1.34 figure would include balls hit by both Mark Teixeira and Brett Gardner, Gardner’s longer drives are flukey.

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