By: Edward Egros

Feb 2017

The Art of the Comeback

Pasted GraphicLast November, arguably five million people attended the Chicago Cubs victory parade, celebrating the team's first World Series Championship since 1908.

Last Summer,
Cleveland hosted hundreds of thousands of Cavaliers fans to celebrate that franchise's first title and the city's first pro championship in more than half a century.

This year in New England, they constantly win. We move on.

The common storyline among these three winners is "The Comeback". The Cubs overcame a 3-1 deficit in the World Series to claim their championship in an extra-inning Game 7, the Cavaliers also stormed back from down 3-1 in the NBA Finals and the Patriots trailed Atlanta by 25 in the second half of Super Bowl LI, to win in overtime. These comebacks were also nearly unprecedented.
Only five teams had come back from down 3-1 to win the World Series before the Cubs. Cleveland became the first NBA team to overcome a 3-1 deficit in the Finals to win. And, New England's 25-point comeback win is the largest in Super Bowl history. The second largest ever is merely ten points.

This confluence of sports drama may seem like supernatural intervention, but perhaps it can be explained in earthlier terms. In 2011, Brian Skinner published "
Scoring Strategies for the Underdog: A General, Quantitative Method for Determining Optimal Sports Strategies". Skinner explained how underdogs must call riskier plays to have a chance at success. In this case, we can refer to teams significantly trailing in series and games as underdogs when their probability of winning is significantly below 50%. Calling riskier plays might mean getting shellacked, but by finding specifically how much riskier a team should get, it might be the only way for those trailing to win.

Baseball closers are niche pitchers, often asked to pitch only one inning, with his team holding the lead. Aroldis Chapman, the Cubs' closer, came in to pitch 2.2 innings in Game 5, 1.1 innings in Game 6 and 1.1 innings in Game 7. Chapman had one day of rest and pitched Game 5, another day of rest before Game 6 and no days off in Game 7. While he did allow three earned runs in the last two games, Maddon believed the risky strategy of extending his closer was the only way to overcome his 3-1 deficit. Chapman did allow runs, but it left other relievers fresh for longer games. Hitters were also asked to swing for home runs, not mere singles or doubles. The Cubs ranked 13th in home runs last season, but in the World Series, they recorded at least one home run in games five, six and seven, en route to their title.

In basketball, Skinner's paper discussed two key concepts pertinent to the Cavs: how often to shoot 3's and when to stall. The logic in the first case is, depending upon how many possessions are left in the game, a team should resort to shooting triples when reaching its critical threshold. In the regular season, Cleveland ranked 7th in the NBA in three-point shooting percentage and 3rd in three-point shooting attempts, but going up against the Golden State Warriors who ranked first in both categories. The Cavs' two of the three highest rates of three-point shooting in that series
happened in games 6 and 7, two must-win games. As for pace, while Golden State had the second most possessions per 48 minutes in the NBA, Cleveland ranked 27th out of 30 teams. However, the Cavs played a faster pace for games 5 and 6, both resorting to a style more like the Warriors and not shortening the game like it is suggested for underdogs. It is worth noting there was a slower pace for Game 7, the most dramatic in the entire series.

Lastly, the Patriots helped themselves and the Falcons maimed themselves because of risk-taking.
Once Atlanta led 28-3, New England resorted to 40 pass plays (including sacks) and just 10 rushes. Before the deficit, the Patriots passed the ball 34 times and ran it 15 times, relying significantly more on the ground attack. Also, some of Brady's longest completions occurred in the 4th quarter during the comeback. Defensively, Matt Ryan and the Falcons leaned towards passing more frequently in the final minutes than sticking to the ground game, which would have taken more time off the clock. Perhaps the most egregious example was when Atlanta had the ball at the New England 22-yard line with 4:40 left in the game and leading by eight. Instead of running the ball three times and going for a two-possession lead, a sack, a pass (wiped away by offensive holding) and an incompletion took the Falcons out of field goal range AND gave Tom Brady 3:30 to tie the game. Overall, even play-count disparity factored into the outcome; Brady kept the Falcons' defense on the field and Ryan could not give his teammates a break.

Teams in any sport can calculate when it is time to run riskier plays. Many recent and high-profile examples suggest comebacks are more possible than ever before, when the right tactics are implemented.

There is a postscript: win probability charts have become more popular than ever. But these games and series show something seemingly calculated to have a .7% probability of happening can occur. Because underdogs can increase their own variance with their playcalling, perhaps these charts need to be updated in some way. Fortunately, this discussion is ongoing.

A New NCAA Tournament

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There's no doubting the increased awareness of analytics in predicting the NCAA tournament field in college basketball. Instead of just diagnosing a team's record against the Top 50, it's Rating Percentage Index or Ken Pomeroy rankings, that are becoming more commonplace. It has gotten to where data scientists are actually meeting with the NCAA to determine if one metric should be used above all others to pick tournament teams.

Perhaps surprisingly, data scientists want simpler criteria for picking teams: who wins, who loses and who have you played. This is opposed to other explanatory variables used in more advanced metrics, like margin of victory and offensive/defensive efficiency. Coaches, on the other hand, would prefer more complex formulae for determining the tournament field. Logically, this approach makes more sense from their perspective, because of competition. If a coach has figured out a style of play or way to schedule opponents that increases the likelihood of making the tournament, they develop a competitive advantage. Data scientists want to keep it simple for fans, coaches want a figure out a competitive advantage.

Perhaps in this same spirit of transparency, the tournament selection committee released "in-season" projections for the first time ever, one month before Selection Sunday. It only has the top four seeds of every region, but it is added information for where highly ranked teams really sit. As with any analytic project, more data "usually" means more robust forecasts. Already, it is easier to make more accurate assumptions and offer a better glimpse as to what the committee is looking for.

However, these in-season projections do not include the full field of 68, and what usually causes the most consternation is simply who does and does not make the dance. While it makes sense not to include the full field because you have to assume certain conference champions in mid-major conferences, something that would include all "at large" teams would provide even more information as to the criteria for inclusion.

Nothing is easy about picking 68 teams to play in a tournament, and while analytics may be helpful in forecasting a Final Four, easy-to-understand criteria can help teams and fans quell any controversy.