Monday, January 23, 2012
Analyzing Harbaughs' fourth-down calls
Rob Carr/Getty ImagesIn the conference championships, the stakes are undoubtedly high. So every decision will be analyzed, with hindsight always being 20-20.
Joe Flacco's incomplete pass on 4th-and-6 hurt the Ravens chances in the AFC Championship against the Patriots, but going for it was statisically the right move.
But regardless how the move turned out, we can analyze the decisions using win probability to find if the move actually gave a team a better chance to win.
So how did some of the key decisions in Sunday’s games shape up?
John Harbaugh Got It Right
With just under three minutes remaining in the fourth quarter, the Baltimore Ravens faced a 4th-and-6 from the New England Patriots’ 33-yard line trailing by three. Ravens’ coach John Harbaugh chose to go for it, but didn’t make it, leading to a turnover on downs.
However, according to ESPN Stats & Information’s win probability tool, this was the right decision. Here are the two options Baltimore had and the expected win probability for each choice.
• Go for it: Taking into account Baltimore’s win probability if they do or don’t convert on the play, as well as the rate of success of teams going for it on fourth-and-six since 2001, the Ravens’ expected win probability choosing to go for it was 29.7 percent.
• Attempt a field goal: If the Ravens make the field goal, their win probability is a 43.8. With a miss, it’s 14.9. Given kicker Billy Cundiff’s career 33.3 success rate on 50-plus yard field goals on kicks outdoors, Baltimore’s expected win probability going for it was 24.5 percent.
Ultimately the Ravens did not get the first down and wound up losing, but they did play the percentages correctly in this situation.
Jim Harbaugh Got It Wrong
On the other hand San Francisco 49ers coach Jim Harbaugh chose safe strategy when faced with his fourth down decision, this one in overtime.
San Francisco had a 4th-and-1 from its own 31-yard line. The common strategy taken in this situation by NFL coaches is to punt. However, in overtime, possession of the ball is worth a lot more than it is in most regulation circumstances because of the sudden-death rules.
Here is what ESPN’s win probability tool says about San Francisco’s options.
• Go for it: Since 2001, teams going for it on fourth-and-one convert nearly 65 percent of the time. Taking into account the 49ers’ win probability if they convert with a one-yard play and if they don’t, their expected win probability if choosing to go for it was 52.1 percent.
• Punt: 49ers’ punter Andy Lee’s average net punt during the season was 44 yards. If Lee had matched that number, the New York Giants would’ve gotten the ball at their own 25, and the 49ers’ win probability would be 48.9 percent.
So by choosing to punt the 49ers cost themselves a little more than three percentage points of win probability.