Monday, February 07, 2011

Suboptimal Super (Bowl) Decisions

So this stuff gets written about to death on the many NFL stats blogs, but it continues to boggle my mind and was a great excuse to crank out a post, so I figured I'd throw some thoughts up on the blog. I'm just going to comment briefly on one choice by either head coach in the waning minutes of the game.

Packers have the ball, 2nd and Goal, at the Steelers 7, and the Steelers have one timeout left. Short pass nets 2 yards, clock is running with about 3 minutes left. Inexplicably, the Steelers choose to let the clock run instead of using their last timeout. Let's take a closer look:

When the goal is to preserve as much time as possible, a timeout called on defense is much more valuable than one called on offense: on offense, a timeout saves you distinctly less than 40 seconds (because you're not going to burn all of your play clock), whereas on defense it saves you the full 40. So we conclude that the Steelers should use their timeout while on defense.

Next, they can either use it or wait until after 3rd down. However, waiting is a poor choice for a few reasons:
  1. The Packers could score
  2. The Packers could throw an incomplete pass, stopping the clock
  3. A bit more subtly, the Steelers having no timeouts left would add some incentive for the Packers to run the ball, an outcome which is much less likely to produce a game-ending touchdown. 
As it turned out, the 2) happened. So while the Steelers kept their timeout, the kickoff happened with 2:07 left to play. Worse, the kickoff took the clock below 2 minutes, wasting the 2 minute warning clock stoppage. Instead of getting the ball back with about 2:40 left to play and the 2 minute warning, they got it back with 2 minutes and a timeout - a big difference. Really, the Steelers should have called timeout after the Packers completed a short pass on 1st and Goal, and not even waited for 2nd down. Regardless, a poor choice by Steelers Coach Mike Tomlin.

Rewinding a bit, the Packers were faced with their own decision - whether or not to go for it on 4th and Goal from the 5 with 2:10 left, up by 3. Those new to the new-school football stats analysis would think kicking the field goal is a no-brainer - in reality, going for it is the obvious call. I'll let Brian Burke at Advanced NFL Stats walk you through the scenarios:

[The Packers] opted for the easy FG to go up by 6. The Steelers would now need a touchdown, but often, forcing a team to go for the win rather than the tie can be counter-productive. This might be a little abstract, but by channeling your opponent into a more aggressive, and likely more optimal risk/reward posture, might not be smart. In other word, even if GB fails on the 4th down TD attempt, the Steelers are left at or inside their 5 yd-line and are "thinking FG."

From the 5, conversions are successful 37% of the time. A successful conversion puts GB up by 10 points, sealing the win with a 1.00 WP. A failed conversion gives PIT the ball at their own 5 with 2:10 to play, worth 0.87 WP to GB. On net, the go-for-it option is worth a 0.92 WP.

FGs from the 5 are good 97% of the time. Going up by 6 and kicking off is with worth 0.75 WP. A missed FG puts the ball on the 20, worth 0.83 WP. On net the FG option is worth 0.75 WP.

WAIT! Did I just say that missing the FG would be better than making it? Yes, that's exactly what I said, and historically, that's exactly the case. The reason is likely because teams down by 3 play for the FG in that situation, while teams down by 6 are forced to play for the win. Once inside FG range, they pull up and stop taking risks, accepting a long FG attempt that, even if successful, only buys them a tie--0.50 WP. I suspect Tomlin would be thinking differently, so the answer to whether the Packers should have gone for it isn't so clear. But based on league-baseline numbers, and some counter-intuitive thinking, going for it would have been the better decision by large margin, about 0.15 WP.
The WP stuff can be a bit confusing - it means Win Percentage, the chance that a given team will win the game (historically based on the situation that they are in). So basically, going for it would mean the Packers would win 92% of the time, where as kicking a FG would mean a win 75% of the time. It makes sense if you think about it - even it the Packers don't convert, the Steelers are pinned deep in their territory, hoping to kick a FG to tie the game. Burke's last point about the impact of the various situations on play-calling is also an interesting one.

It's incredible how much these suboptimal decisions persist in football. It's been written about a bunch, but for both coaches to make such poor calls in the most important moments of the most important game of the year is quite astounding. 

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