Sports Illustrated’s Tom Verducci is one of the best baseball writers around. In fact, he’s probably my favorite. He respects the valuable research done by sabermetricians, but he also possesses the best characteristics of previous generations of baseball fans. His interest in and knowledge of the game are always evident, and he writes in an engaging style.
With the Super Bowl fast approaching, this week Verducci veered away from the diamond to cover North America’s most popular sport. This in contrast to me, a football writer who this week wrote about tennis. Yeah, the biggest game in my favorite sport is a week away and I wrote about something else. Verducci, obviously, is a much smarter man than I am. Anyway, his article was about the huge home-field advantage enjoyed by football teams in domed stadiums.
In the piece, Verducci presented some statistics that, even if you know football pretty well, look very convincing:
* Four of the past six teams to reach the Super Bowl have been dome teams.
* The Colts and the Saints reached the Super Bowl with below-average defenses, ranked 18th and 25th, respectively.
* A dome team is 15 percent more likely to win at home than a non-dome team at home.
* In 2009, dome teams were .633 at home, while non-dome teams were just .551 at home.
* Peyton Manning has played much better in indoor playoff games than outdoor playoff games.
* Dome teams at home are 7-0 in the playoffs. Teams without a dome are 0-3 at home.
Taken together, that suggests pretty firm support for Verducci’s case. For several reasons, though, you shouldn’t take these numbers at face value. Let’s address those points one at a time.
Four of the past six teams to reach the Super Bowl have been dome teams.
This actually isn’t true. The Colts and Saints are both dome teams, and the Cardinals have a retractable roof, so we’ll count them. The Steelers, Giants, and Patriots all play outdoors. That’s three of the past six teams to reach the Super Bowl. In fact, only four of the last 16 teams to make the Super Bowl played their home games in a dome. The article cherry-picked a cutoff line that made the stats appear to support its thesis. This particular technique of distorting statistics is called multiple endpoints. In fact, I’ve just used it, too (four of the last 16). I stopped at 16 because one more year adds the 2001 Rams, weakening my point.
Let’s go with a nice, round 20 teams: the last 10 NFL seasons. That brings us to five of the last 20 Super Bowl teams playing home games in a dome. This means 25% of Super Bowl teams were dome teams. That’s almost exactly what we would expect: 22.6% of all NFL seasons this decade were played by teams with a domed stadium or a retractable roof. In the whole history of the game, only two dome teams (the ‘99 Rams and ‘06 Colts) have won the Super Bowl. Verducci is arguing trends, so make that two of the last 10 if you like. It’s still 20%, which is about the expected rate, actually a little low. Next Sunday, it will become 27%: about the expected rate, just a little high.
The Colts and the Saints reached the Super Bowl with below-average defenses, ranked 18th and 25th, respectively.
I actually don’t know what this is supposed to prove, but it’s misleading. Teams with good offenses — especially good passing offenses — give up more yardage than teams with bad offenses, both because the pace of the game is faster and because the opponent passes more while it’s trying to catch up. Pass plays gain more yardage than running plays do (averages are 6.2 yards and 4.2, respectively), so teams that are passed against more often yield more yards. The Colts and the Saints have the two best offenses in the NFL; we would expect them to give up a lot of yards.
The Saints forced 39 turnovers in the regular season, second-best in the NFL. They held opposing passers to a 68.6 passer rating, third-best. This was a gambling defense, willing to give up yards in order to make big plays. The New Orleans defense scored seven TDs this season. No other defense scored more than four (Eagles and Titans). New Orleans plays an aggressive defense that gives up yards, but creates opportunities. It ranked 25th in yards, but might have been one of the 10 best defenses in the NFL this season. Indianapolis ranked eighth in points allowed. These were both above-average defenses, not subpar as Verducci’s article implies.
Peyton Manning has played much better in indoor playoff games than outdoor playoff games.
Manning indoors during the postseason: 6-3, 333 ypg, 20 TD, 8 INT.
Manning outdoors during the postseason: 3-5, 230 ypg, 7 TD, 10 INT.
Yes, obviously Manning has played better indoors during the postseason. THE COLTS PLAY THEIR HOME GAMES IN A DOME. All of those dome games were home games, and none of the outdoor games were. So there are two very good reasons for Manning to have better numbers in those indoor games:
1) Home-field advantage.
2) Playing an inferior opponent. In the playoffs, teams that were better during the regular season get home-field advantage. In those nine dome games, the Colts were playing teams that were, on average, 2.5 games worse than them in the regular season. When a team with 13 wins (12.9, actually) plays a team with 10 wins (10.4), at home, won’t the team with 13 usually do pretty well? Wouldn’t you expect the quarterback — especially if he is among the best QBs ever — to have good numbers? A .667 winning percentage, 333 yards, and 5:2 TD/INT ratio is not out of line for what you would expect from Manning in home games against competitive teams.
In contrast, all but one of those outdoor games (Super Bowl XLI, against one of the best defenses in recent memory) were at an opponent’s home field. Playing against a team with home-field advantage, that six times out of eight had a better record, wouldn’t you expect a player to struggle? Is .375, 230 yards, and a couple more INTs than TDs outrageous for Manning in road games against better teams? No. On the contrary, I think it’s about what you would expect. Really, don’t all quarterbacks do better at home and against weaker teams? Yes…
Tom Brady at home during the postseason: 9-1, 193 ypg, 15 TD, 8 INT.
Tom Brady on the road during the postseason: 3-2, 235 ypg, 6 TD, 6 INT.
Don’t let the yards per game fool you: at home, Brady threw more TDs and fewer interceptions, and his team had a much better record. Are Manning’s home/road splits a little larger than we might expect? Yes. Do they demonstrate any clear difference compared to other players in outdoor stadiums? No, they do not.
Verducci even compared Manning to Larry Walker, “a guy who hit .381 at Coors Field, but .282 everywhere else.” He’s basically saying that if the Colts had drafted Ryan Leaf and the Chargers taken Manning, Peyton would be Kerry Collins, the football equivalent of a .280 hitter. For years, Coors Field was the friendliest hitters’ park in MLB and offered the biggest home-field advantage. That has never been the case for the Colts’ home stadiums.