The Super Bowl may be over, but let’s not forget about the NFL just yet.
MLB managers have a new responsibility to consider starting this season. With the introduction of instant replay, John Gibbons and his 29 counterparts around the league must now determine when to use their challenges.
The element of strategy may be confusing at first, but managers must now prepare to use it to their advantage (MLB teams get one challenge per game with the ability to challenge twice if the first challenge is upheld; full explanation here). If they leverage the challenges on big plays, their teams will accumulate small advantages over the course of the season. If they use the challenges on insignificant plays or wait too long, they will be squandering opportunities.
While this represents a new frontier for MLB managers, NFL head coaches have been throwing challenge flags for years. That prompted me to take a closer look at NFL replay to see what their system can tell us about the changes ahead in MLB:
Coaches don’t use all of their challenges
NFL coaches can use two challenges per game, and they get a third challenge if they win the first two. But on average, they used just 0.6 challenges per game in 2013, according to Neil Hornsby of ProFootballFocus.com.
That’s partly because touchdowns and changes in possession are automatically reviewed. As a result, there’s a limited number of bad calls that aren’t looked at a second time. Plus, NFL teams lose one of their timeouts if they challenge and the original call is upheld. Shrewd coaches won’t waste a valuable timeout on an insignificant play, as they only get three timeouts per half.
MLB takeaway: MLB managers aren't betting with anything other than the challenge itself, which increases the incentive for teams to use the challenges more liberally than NFL coaches. In some respects it would make sense for MLB managers to max out on their challenges -- why discard a potential advantage?
But challenging plays routinely could irritate umpires, opponents and players, so managers may elect to save their challenges for major plays. Tony La Russa, the longtime manager who now works for MLB, explained that the league implemented replay to get the big calls right.
"We’re really going for the dramatic miss, not all misses," La Russa said. "This is a challenge for a game-changing play that goes against you, and now you can correct it."
Some types are more successful than others
Hornsby's research shows that some challenges have better success rates than others. For example, when a coach challenged whether a runner was down by contact, he succeeded more than half of the time (29/51). Yet fumble-related challenges succeeded closer to one third of the time (22/68).
MLB takeaway: Expect some types of challenges to be upheld more frequently than others in MLB.
Low-leverage challenges succeeded more often
Challenges succeed less often when leverage increases, according to research by Kevin Meers of Advanced NFL Stats. While Meers stops short of saying there’s a clear relationship, he says “it seems at least possible that officials are less likely to overturn plays that are hugely influential on the outcome of the game.”
It’s also possible that there’s selection bias in play. Coaches are more likely to use their challenges on a low-leverage play when they’re completely sure they’re right. Otherwise it wouldn’t be worth the risk. Meanwhile, coaches might be willing to use challenges on high-leverage plays even if they aren’t quite sure they’re right. That approach boosts the success rate on low-impact challenges and lowers the success rate on high-impact challenges.
MLB takeaway: Don’t be surprised if low-impact decisions are overturned more frequently than high-impact calls.