Repeated often enough over the years by players, coaches, newspaper columnists, and ESPN talking heads, clichés have the habit of becoming fact to the sports cognoscenti. These truisms tend to shape debate among fans and inform the decisions of team executives.

But as we've learned from the stat-head revolution led by the likes of Bill James as well as the good folks at Basketball Prospectus, Baseball Prospectus and Football Outsiders, there may be more myth than fact behind many of our long-held beliefs.

The latest salvo in the revolution comes from Jon Wertheim, a senior writer at Sports Illustrated (right), and Tobias Moskowitz, a finance professor from the University of Chicago, with their Freakonomics-influenced book Scorecasting: The Hidden Influences Behind How Sports Are Played and Games Are Won.

Like Moneyball and Soccernomics before it, Scorecasting crunches the numbers to challenge notions that have been codified into conventional sports wisdom.

Wired.com recently sat down with Wertheim to talk about notions of home-field advantage, referee bias and the decades of futility from his beloved Chicago Cubs.

Wired.com: How did you and a University of Chicago professor team up to write this book?

Jon Wertheim: He's a friend from way back. We went to camp together in the '80s, grew up together, and played tennis as a doubles team together. It wasn't just two random guys who met on the street. We would talk about how there was so much data for sports and so many sports truisms that people take for granted that are left unexplored, so we thought, Why don't we play around on this?

Wired.com: How did you go about figuring out what truisms you wanted to address?

Wertheim: We brainstormed like we were sitting a bar with your buddies watching a game, and you say, "Is that the right decision to punt or to go for it?" Or "Does defense really win championships?" They’re the questions every sports fan wonders about, like, "Is it really true that home team wins more often?" We assume it is and we crunched the data and, sure enough, for a century's worth of games in every sport the home team wins more often.

Wired.com: So it wasn't just about overturning conventional wisdom. You found some of those old clichés to be true?

Wertheim: The cliché that the home team wins more often is 100 percent accurate, so there's nothing to overturn there. That there's "no 'I' in team" is flatly untrue. The best teams almost always have a top-tier player, if not two of them. But some things we researched, like draft strategy, are less obvious. It leaves you saying, "Well, X, Y, and Z have to also fall into place." So in some cases, you can just topple the conventional wisdom. Some of the wisdom out there isn't patently false; it just isn't quite what we always thought it was.

Wired.com: So why does the home team win more often?

Wertheim: What's really interesting is how consistent that truism is. The WNBA has almost the exact same home winning percentage as the NBA. A soccer league in Central America is almost the same as the Premier League. Japanese baseball has almost the same as MLB.

Before you even dig into the "why?" of home-field advantage, you see the data that 100 years ago the home winning percentage in Major League Baseball was almost exactly the same as it is today, and you find the same in other sports.

I think most people think, "Well, you’re playing at home and you’ve got people cheering for you and booing the other the guy," but we didn’t find that to be the cause. Then you have the theory that home teams get to sleep in their own beds and road teams had to fly in the night before, but that didn’t seem to be the case either.

Wired: Right. You made the point in the book that travel has gotten so much better than 100 years ago, but winning percentage didn’t change from when teams were on buses to now, when they’re taking charters.

Wertheim: Yeah, and in games like when the Angels play the Dodgers or the Ravens play the Redskins – games where there’s negligible travel – the winning percentage stays the same. If you fly across the country, you’re not losing any more than you are when you’re the Chicago White Sox playing across town at Wrigley Field.

So we looked at how games are called and that’s where the data went berserk. Yellow and red cards in soccer, calls in the NFL before and after replay’s implementation, called balls and strikes in baseball – that’s where we saw games are called totally differently based on where they’re played. And the more attended the games are, the more striking the bias.

Also, how close the fans are matters. In some European soccer stadiums, the track acts as a moat to keep the fans away and that reduced bias. So everything we found pointed to the home teams winning more because the games are being called differently.

Wired.com: That kind of explains Super Bowl XL when the Seattle Seahawks got jobbed by the officials in a way we hadn’t seen in a Super Bowl before.

Wertheim: Exactly, that’s right. The percentage of fans made that basically a home game for the Steelers.

The other thing we found out about officiating is "swallowing the whistle." Officials don’t want to insinuate themselves on the game. It’s not necessarily of a bias, but the refs want to stay out of the game in the waning minutes.

Wired.com: Like when there’s a touch foul in the NBA postseason and you hear people say, "You don’t make that call in the playoffs."

Wertheim: Yeah. When you think about it is absurd, like with Serena and her foot fault in the US Open, you make that call or you don’t, but it’s something we’ve become accustomed to and that gets to the officials.

We also wrote about the Chris Webber "timeout game." In the last 30 seconds the UNC-Michigan Championship Game and Webber gets the ball and has the most egregious travel ever. If this happens at my kids’ grade school basketball game, you have to call it. It’s three loping steps – he even stops for a second and looks around guiltily. But nothing, they let him play. That’s subjective. I mean, not totally subjective, but it’s easier to let a travel call slide. Well, he signals for timeout and that’s a call where there’s no room for subjectivity. It demonstrated that there are points when referees have to act and times when they can let them play.

Wired.com: You guys show that refs are biased toward the home team and you show with PitchFX that umpires adjust their strike zone depending on the situation, so do you think we should just get rid of umpires in baseball?

Wertheim: That’s a good question. PitchFX calls it accurately; it’s unambiguous, so from a fairness perspective it’s hard to argue against it. But as fans we like whistle swallowing. I don’t think fans overall are opposed to games being called differently at different times. We found that a player like Albert Pujols gets very few called third strikes, but also very few ball fours because the umpire internalizes that fans want to see him put the ball in play – you want him to strike out swinging, you want him to hit a home run, but you don’t want a judgment call. So, in some ways, whistle swallowing is following what fans want.

From a fairness perspective, if you have the capacity to call balls and strikes pretty flawlessly, it’s hard to argue against that. But I think we want more from our officials from a robotic ball and strike. I think we like to have our officials to have sensitivity to the rhythms of the game.

Wired.com: Speaking of flow of the game, you two analyze the idea of momentum and the "hot hand" in sports and conclude that it doesn’t exist.

Wertheim: There was a famous study by these two Nobel Prize winners a generation ago that made that case and we found the same thing. There’s not a "hot hand" per se, but there’s no doubt that there are streaks and that a guy can hit four in a row. The same way that a batter that bats .250 doesn’t go out, out, out, hit, out, out, out, hit. When you flip a coin it will be 50/50, but that doesn’t mean it alternates. I think people don’t understand the probability. If you talk to athletes there’s no doubt there’s a "hot hand" and there’s no doubt that they’re "feeling it," but it’s a hard case to make statistically.

Wired.com: You’re a tennis guy, so think about when you’re actually playing. Are there times when you feel physically and mentally locked in and you’re just hitting lines and you have a "hot hand"?

Wertheim: Yeah, and one of the hardest things about all of this is isolating variables. If a guy’s wife dumps him the night before the game, that is something you can’t control for. Again, there’s no question that some days athletes are healthier than others, some days they feel better, some days the climate is more conducive, but as a matter of probability, it doesn’t really support the idea of a hot hand.

Wired.com: As a matter of probability, the Chicago Cubs are certainly an anomaly. Why did you want to write about them?

Wertheim: One of the first chapters we did was on the Cubs because we both like them and grew up in the Midwest. We found some really cool things and went forward from there. The Cubs really are bad – it’s not just because they’re unlucky and cursed by a goat.

Wired.com: You two make a pretty convincing case that plenty other teams are more "unlucky" than the Cubs and that their shortcomings have been more a result of mismanagement. Has the team just been milking the idea that it's "cursed" to absolve itself of blame?

Wertheim: I don’t think the Cubs intentionally lose games, but their incentives to win economically are a lot different than most other teams. I don’t think that it’s a leap that at some level it leaks down to the players that no matter what the fans are going to come and WGN is going to be there and Cubs baseball kind of has this persona now.

Wired.com: That’s another theme of your book. You’re not just parsing actuarial tables, you’re trying to get to the psychology behind the numbers. There are places in the book where you show that the statistics favor one action, but our own psychology gets in the way.

Wertheim: We talk about that with punting and going for it on fourth down. You’re never an idiot for punting. You’re called "conservative," but if you go for that fourth down and you turn the ball over, you get a lot of heat. So coaches will make the sub-optimal choice statistically, but they’re not going to subject themselves to all sorts of hell if they go for it. We do that in life, too. If you’re a fund manager, no one is going to fire you if you invested a client’s money in Walmart.

Look at New England coach Bill Belichick and how he almost never went for it when he was the head coach in Cleveland. When he was there, his job was in peril, there was a rabid fan base, and the team was not doing well. But after he goes to New England and wins three Super Bowls, he's called a genius and has job security and his whole strategy changes. The math didn’t change.

Wired.com: As the stats revolution grows, will it help change that psychology?

Wertheim: There’s still Joe Morgan. You still have this segment of the population that thinks, This is just geeks and their numbers and they know it when they see it and what the right play call is. I had someone in the NBA once tell me, "A few years ago, it was all about taking kids out of high school and look at Kwame Brown. Then it was all about taking European players and you look at Ricky Rubio and similar busts and I guarantee that in a few years no one is going to care about your pie charts and there’s going to be a new trend."

So there’s still a segment that thinks this is a trend just for the geeks, but there are enough credible people who support analytics. No one is saying every single time that you follow the number you’re going to be successful; you’re just tilting the odds in your favor.

Follow Jeremy Repanich on Twitter @racefortheprize

Photo credits: Top: Flickr/stevensnodgrass, CC; Wertheim: David Barry. Graphs: Courtesy Jon Wertheim