MLB.com Columnist

Mike Petriello

Short porches may mean more HRs in Houston

Minute Maid Park had the shortest average home run distance in 2017

Short porches may mean more HRs in Houston

Wednesday's World Series Game 2 at Dodger Stadium was memorable for so many different reasons, but perhaps none more so than the record-setting barrage of home runs. We saw eight homers between the two clubs, topping the Fall Classic record of seven set in 1989's Game 3, as the Astros evened the series at 1-1. Five of those dingers came in extra innings, besting a postseason record previously held by the three that came in Game 1 of the Boston-Cleveland 1995 American League Division Series. (It was also more extra-inning homers than we've ever seen in any regular or postseason game.)

If you liked watching the ball fly out of the park, you're in luck: Now the Series shifts to Houston for the next three games, and thanks to the short fences in both left and right, there's probably no easier park in the game for a (certain type of) fly ball to leave the yard.

Gm Date Results Video
1 Oct. 24 LAD 3, HOU 1 Watch
2 Oct. 25 HOU 7, LAD 6 (11) Watch
3 Oct. 27 HOU 5, LAD 3 Watch
4 Oct. 28 LAD 6, HOU 2 Watch
5 Oct. 29 HOU 13, LAD 12 (10) Watch
6 Oct. 31 LAD 3, HOU 1 Watch
7 Nov. 1 HOU 5, LAD 1 Watch

Let's start with the simplest way to express that, which is looking at average home run distance by venue, which immediately tells you a lot about that park.

2017 shortest average home run distance, by venue
392 feet -- Minute Maid Park, HOU
392 feet -- Great American Ball Park, CIN
394 feet -- Safeco Field, SEA
Major League average -- 400 feet

This doesn't tell you that the Astros have weak hitters, because obviously they don't; they actually had the best offense we've seen in years. In the same way that Kauffman Stadium's AL-high 409-foot average tells you more about the enormous size of the outfield than it does about the strength of the Royals' hitters, Minute Maid Park's 392-foot average is dragged down by the short distances down the lines, especially in left field, where the Crawford Boxes are just 315 feet away. Only one stadium has a shorter left field, and Boston's Fenway Park makes up for that with the 37-foot tall Green Monster. (The left-field wall in Houston is half that height.)

Since hitters don't always need to get all of the ball to send it out in Houston, it's possible for a "softly hit" ball that would have been an easy out somewhere else to become a home run at Minute Maid Park. We've been using 95 mph and over as the break point for a "hard-hit" ball, since it's above that mark that success really comes, and as you'd expect, an overwhelming majority of homers are "hard-hit." We saw over 6,100 homers in the Majors in 2017, and nearly 5,800 of them -- that's more than 95 percent -- were "hard-hit."

• Gear up for the World Series: Astros | Dodgers

But in Houston, just 89 percent of homers were "hard-hit," with at least 95 mph of exit velocity. That was the lowest mark in the Majors, and it means that we saw more "softly hit" homers there than anywhere else.

Most home runs with exit velocity below 95 mph, 2017
23 -- Minute Maid Park, HOU
14 -- Great American Ball Park, CIN
13 -- Coors Field, COL

It's possible to get the ball out to right field, too, of course; at 326 down the line, it's in the shallowest-third of Major League right fields. But this is really a story about those boxes in left field, because of those 23 softly hit homers, 16 of them came from righty batters, the majority pulling the ball to left.

We can show some specific examples, too. By combining exit velocity and launch angle, we can look at hit probability for every batted ball. Based on those two factors, we can see how likely a batted ball was to be a hit, independent of defense or the ballpark, things the hitter simply cannot control.

Of those 6,100-plus home runs this year, three of the 10 with the lowest hit-probability numbers came in Houston.

Marisnick's solo roundtripper

Lowest hit probability home runs, 2017
1 percent -- Jedd Gyorko, Aug 17, at PIT
2 percent -- Jake Marisnick, June 14, at HOU
2 percent -- Lorenzo Cain, July 29, at BOS
2 percent -- Tyler Flowers, June 21, at ATL
3 percent -- George Springer, Sept 17, at HOU
3 percent -- Josh Reddick, Apr 19, at HOU

(four others were tied at 3 percent)

For example, take a look at that Springer home run:

We've seen this phenomenon in the postseason as well. Think back to Game 6 of the AL Championship Series, when Houston's Jose Altuve gave Houston a 4-1 lead in the eighth inning with a solo homer. With an exit velocity of 93 mph and a launch angle of 24 degrees, that ball had a hit probability of 21 percent, and balls with that specific combination go for a home run roughly 1 percent of the time.

Altuve's solo homer in the 8th

While the Dodgers haven't played in Houston this year, they're certainly aware of how the park plays, and it almost surely factored into their decision to start fly-ball pitcher Rich Hill in Game 2 in Los Angeles instead of in Houston for Game 3, preferring to save Yu Darvish for this start.

We also know that the Dodgers have more than a few hitters who love to get the ball off the ground, which is the only way these fences will factor in. No team reduced its ground-ball rate by more than 3.5 percentage points from last year than the Dodgers; postseason hero Chris Taylor rebuilt his swing in some way to emulate the success of Justin Turner. Among the 30 teams, only four had their righty hitters turning a higher percentage of their batted balls into flies or liners than the Dodgers did.

"If I fly out four times, I had a great night, because I didn't hit a ground ball," Turner said when we asked him about his career resurgence back in March, an approach that could serve him very well in Houston.

Statcast: Turner's unique homer

Of the 230 righties who had at least 100 balls in play, Turner's 62-percent fly-ball/line-drive rate was third highest.

Oddly enough, however, Minute Maid Park played as an overall pitcher's park this year, partially because the extremely deep center field -- even after the removal of Tal's Hill -- makes it tough to get the ball out in that part of the park. This isn't about Houston playing like Coors Field; it's about one very specific kind of batted ball that more easily turns into a home run here.

As we know, there are a ton of different reasons for all the homers we're seeing. We know that hitters are using data to improve their strategies as they try to get the ball in the air. We know that the increase in strikeouts and the increase in homers are linked; we know that the record heat we saw in Los Angeles helped at least one or two homers get over the fence; we're awash in studies about the composition of the ball. All of those are factors.

But in Houston, the answer might be the simplest of them all: The fences down the lines aren't far away. You don't have to get all of it to get all of it.

Mike Petriello is an analyst for MLB.com and the host of the Statcast podcast. This story was not subject to the approval of Major League Baseball or its clubs.