This is something that belongs in the long-overdue category. In effect, I've automated myself, which is not something one does eagerly.
The 4th Down Calculator estimates the Expected Points (EP) and Win Probability (WP) values for all three options--go for it, punt, and field goal attempt. All you need to do is enter the game state at the time of the 4th down and click 'calculate'. A table of results will appear that lists:
- the league-average success rates for conversion attempts and FGs
- the EP and WP values for success and failure
- the total EP and WP values based on an expected utility calculation
- and lastly, a break-even conversion probability
The break-even conversion probability is the minimum chance that a successful conversion would make going for it worthwhile. This value can be important when considering specific match-up and play call considerations.
Results based on EP values will provide greater "resolution" and precision, but are only accurate during normal football situations. This is when the effects of score difference and time remaining are small and the game is simply one of net score optimization. When score and time become a factor, it's best to rely on results based on WP values, which account for score and time.
For example, up by 7 with 8:14 remaining in the 2nd qtr, on 4th and 11 from the PHI 33, CHI attempted a 51-yd FG. According to the 4thdownulator, the EP value for going for it is 0.40 and the EP value for the FG attempt is 0.67. The WP value for going for it is 0.75 and the WP value for the FG attempt is 0.77. In this case, both models suggest kicking the FG was the better decision.
In this scenario, the break-even conversion probability is 34% based on EP calculations and is 43% based on WP calculations. I'd rely more on the EP model than the WP model in this case because it offers more precision while time and score are not yet a factor.
Note that the results from the 4th Down Calculator will not always match the analysis I do for some situations depending on certain factors. In end-game situations, I'll often do a more refined analysis using additional techniques and make adjustments for timeouts remaining.
The 4th Down Calculator is always accessible through the WP Graphs menu.