Rising Rates Revisited

When we last checked in on 2009 home-run rates, April was just about in the books, and was providing a strong indicator that this year’s overall home-run rate would finish ahead of last year’s. But while the performances of Adrian Gonzalez (22 homers) and Raul Ibañez (20), and the frequency with which balls continue to fly out of Yankee Stadium (1.81 homers per team per game) suggest a homer-happy season, the reality is that rates have slowed considerably.

Through April 25-the cutoff point for the data used in my previous piece-batters were homering in 2.79 percent of their plate appearances and averaging 1.082 home runs per team per game. By the end of the month-a period shortened by the World Baseball Classic having pushed Opening Day back a week-those figures had dropped to 2.71 percent and 1.051 per game. Thanks to a May where the fences seemed to move outward (2.58 percent and 0.999 per game), the overall rates are now ringers for last year’s numbers, and would be among the lowest of the post-strike era if the season had ended on June 9:

Year  HR/PA   HR/TmG
2009   2.61   1.009
2008   2.60   1.005
2007   2.63   1.020
2006   2.86   1.109
2005   2.69   1.032
2004   2.89   1.123
2003   2.78   1.071
2002   2.71   1.043
2001   2.92   1.124
2000   2.99   1.172
1999   2.91   1.138
1998   2.69   1.041
1997   2.64   1.024
1996   2.80   1.094
1995   2.60   1.012

After all of the breathless stories during the early weeks, those new numbers don’t exactly make headlines, but take heart, sensationalists: at the very least it can still be said that home runs are slightly ahead of last year’s pace. April 2009 saw 17.1 percent more homers per game than last year. May saw just a 3.3 percent year-over-year rise, though June’s numbers, such as they are, are down 12.3 percent. Through the end of last May, a total of 840 games, home runs were being hit at a rate of 0.932 per team per game. Through June 9 of this year, 870 games, they’re 8.3 percent above that rate.

The numbers reveal more once we break them down by leagues:

Lg    2009   2008-td   2008-f
AL   1.088    0.869     1.001
NL   0.939    0.987     1.008

2008-td: The 2008 "to-date" rate, using the end of May as a
  close-enough cut-off point to account for this year's later start.
2008-f: The full-season rate for 2008.

Here we see a sharp contrast: home runs in the AL are up 25.2 percent over this time last year, while homers in the NL are down 4.9 percent. The obvious explanation would seem to be the addition of the two new New York parks. Regarding homer-friendly Epic Fail Stadium, last month’s Accuweather report surmised that the stadium’s design, with its gentle slope from the top of the stadium down to the field, could be creating a wind tunnel which was causing the home-run surge. In this week’s follow-up, meteorologists suggested that the surge is being caused by shorter fence dimensions created by less gentle curves between the distance markers than the old park, a point suggested by Marc Normandin last month. You don’t need a weatherman to know which way the wind blows.

Meanwhile, Petco East… er, Citi Field ranks 23rd in the majors at 0.833 homers per team per game. That’s below average, of course, but with the bandbox in the Bronx so far above average, the two are still combining for 1.339 homers per game, a rate that would rank third if it represented a single park. Excluding those two and their predecessors-which averaged an ahead-of-the-curve 1.031 per game last year-from the picture:

Lg    2009   2008-td   2008-f
AL   1.032    0.858     1.002
NL   0.946    0.989     1.003
ML   0.986    0.928     1.003

Eliminating the New York parks from both years, we find that per-game home-run rates are up 6.3 percent over last year at this time, but that the current figures would still finish 1.6 percent below the full-season 2008 rate because of a June-July uptick (1.073 per game) that pushed things back toward normalcy. Not that things are particularly stable once we remove the Big Apple parks:

Park         2009     2008  %Change
Yankees     1.810    0.988    83.3*
Phillies    1.462    1.167    25.3
Rangers     1.431    1.259    13.6
Orioles     1.317    1.275     3.3
Brewers     1.269    1.084    17.1
D'backs     1.188    0.975    21.8
Rays        1.179    0.987    19.4
Reds        1.161    1.321   -12.1
Twins       1.152    0.852    35.2
Blue Jays   1.129    0.772    46.3
Astros      1.094    1.218   -10.2
Cubs        1.058    1.148   - 7.9
White Sox   1.047    1.378   -24.0
Red Sox     1.019    0.907    12.2
Marlins     1.016    1.049   - 3.2
Rockies     1.000    1.074   - 6.9
Angels      0.962    0.951     1.1
Nationals   0.919    0.925   - 0.6
Tigers      0.911    1.247   -27.0
Indians     0.889    0.951   - 6.5
Mariners    0.850    0.833     2.0
Cardinals   0.838    0.994   -15.7
Mets        0.833    1.074   -22.4*
A's         0.828    0.791     4.6
Padres      0.817    0.840   - 2.7
Dodgers     0.726    0.741   - 2.0
Royals      0.700    0.759   - 7.8
Pirates     0.615    0.944   -34.8
Braves      0.567    0.889   -36.3
Giants      0.500    0.741   -32.5

*: New parks for 2009

Some of the parks are right in line with last year’s rates, while others are waaaay off; excluding the two New York parks, more than half of the rates have changed by at least 10 percent in one direction or the other. US Cellular Field and Comerica Park, two of the top five home-run parks last year, are down more than 20 percent, while a third, Great American Ballpark, is down by more than 12 percent. Among last year’s bottom five, whatever they’re calling the Skydome these days is up by nearly half, while AT&T Park is actually down by nearly one third. Personnel changes, streaks and slumps, schedule imbalances, and odd weather patterns, as well as good old randomness are running amok in these small samples; remember that even a full season isn’t enough to divine the magnitude of a ballpark’s true effects. As with yesterday’s piece, gawk at the freak-show circus while it’s in town, but don’t invest too heavily.

Strength of Schedule: the Sequel

In the spirit of checking in with some of this spring’s earlier work, I went back and calculated each team’s PECOTA-based strength of schedule first through June 9, and then for the rest of the season, in the service of pointing out a few extremes. Here are the five hardest and the five easiest slates thus far:

Team        Opp W%
Rays         .521
Marlins      .520
Red Sox      .519
Indians      .515
Orioles      .513
Tigers       .489
Mets         .488
Astros       .487
Cubs         .484
White Sox    .482

The Rays’ early struggles are placed in their proper context, and Indians fans can take heart that their team’s lousy showing may have something to do with the severity of their schedule, along with a myriad of other things-a pitching staff that ranks 13th in the league in both SNLVAR and WXRL, injuries to Travis Hafner and Grady Sizemore, and poor personnel management on the part of Mark Shapiro and Eric Wedge. White Sox fans get no such comfort. Here are the extremes going forward:

Team        Opp W%
Blue Jays    .529
Orioles      .522
White Sox    .517
Marlins      .511
Nationals    .509
Twins        .489
Dodgers      .486
Cubs         .485
D-backs      .484
Indians      .483

And as an excuse to provide the full slate of data, here are the 30 teams ranked by what I’ll call the Uphill/Downhill factor, the change between the two segments:

Team           A      B    Change
White Sox    .482   .517    .036
Blue Jays    .499   .529    .030
Mets         .488   .508    .020
Astros       .487   .505    .018
Braves       .492   .507    .015
Orioles      .513   .522    .009
Mariners     .493   .502    .009
Tigers       .489   .497    .009
Pirates      .497   .505    .008
Rangers      .500   .507    .007
Royals       .497   .502    .005
Nationals    .505   .509    .004
Rockies      .501   .504    .003
Cardinals    .493   .494    .002
Cubs         .484   .485    .001
Brewers      .495   .493   -.002
Yankees      .507   .505   -.002
A's          .500   .496   -.004
Reds         .495   .491   -.004
Dodgers      .491   .486   -.005
Phillies     .505   .499   -.006
Marlins      .520   .511   -.009
Giants       .507   .495   -.012
D'backs      .496   .484   -.013
Angels       .506   .493   -.013
Padres       .512   .497   -.015
Red Sox      .519   .502   -.017
Twins        .512   .489   -.024
Rays         .521   .494   -.027
Indians      .515   .483   -.032

Lest anyone mistake these for splits between season halves, I’ve creatively labeled the two segments “A” for the games played through June 9, and “B” for the remaining schedule. If you thought the post-season hopes of the Blue Jays, who have won just seven of their last 20 games, were in trouble before, get a load of the mountain they have to climb. Relative to the Rays, who are four games behind them in the standings but at the other end of the spectrum here, they’ve got a schedule that’s 35 points harder (about six games) the rest of the way, and representing a 57-point swing from the season to date. Elsewhere among contenders, the Twins, who have the fifth-easiest schedule the rest of the way, get the benefit of a 33-point swing relative to the Tigers, and if you want, you can put on the rose-tinted glasses to view the Indians, who with the easiest remaining schedule have a 41-point swing in store relative to the division leaders. In the AL West, the Angels have a 20-point swing relative to the Rangers.

Over in the NL, the Mets have an upcoming schedule that’s nine points harder than that of the Phillies, representing a swing of 26 points from the season to date-a bad sign for the Flushing faithful. There’s almost no movement atop the crowded NL Central, though the Cubs, who have the majors’ easiest schedule overall, get a bit of protection amid their slew of injuries. The Dodgers, with the fourth-easiest remaining slate, leave the West’s also-rans with only minimal gains in the scheduling department.

With nearly 60 games under each team’s belts, you’re probably wondering why I haven’t bothered to incorporate the actual results into these. The answer is that it’s a major schlep full of manual labor, and more worthy of the season’s midpoint, either at the actual 81-game mark or the symbolic one at the All-Star break. Hopefully this provides some food for thought until then.

Thank you for reading

This is a free article. If you enjoyed it, consider subscribing to Baseball Prospectus. Subscriptions support ongoing public baseball research and analysis in an increasingly proprietary environment.

Subscribe now
You need to be logged in to comment. Login or Subscribe
Good stuff. Thanks!
In the AL West the Rangers are (by the depth charts) predicted to go 43-61 the rest of the way. The Angels are predicted to go 51-55 the rest of the way (not counting the June 10th loss). As these two teams have 16 games left to play against each other, how much are those head-to-head matchups influencing the strength of schedule numbers? I'd be curious to see their SoS numbers for the rest of the season with those 16 games left out.
Interesting point. Since the Angels were projected as a .500 team, the Rangers' remainder doesn't move much, climbing to .509 the rest of the way without the Angels games. But with the Rangers projected so to be so poor (.435), removing those games from the Angels' slate bumps their remainder up to .505.
"The answer is that it's a major schlep full of manual labor"

Jay, two words: in terns.
An overhead photo of Yankee stadium could be used to get the true dimensions. Its 90' to 1st base, you can assume that's accurate and use that and some trigonometry to figure out the actual dimensions.