Rushing touchdowns are the holy grail of fantasy football. They're the most scarce scores. Everyone starts the draft by picking 2 RBs (except the guy who always takes Peyton Manning first).
Rushing TDs are a product of a great running game, right? That's only half true. Rushing TDs have just as much to do with a good passing game as a running game. That's not shocking news to most serious football fans. No team can run the ball all the way down the field without at least a few pass completions. But the extent to which rushing TDs are dependent on the passing game may surprise some.
Rushing TDs correlation with:
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Team Yds/Rush 0.50
Team Yds/Pass Att 0.46
Going a little deeper, we can run a quick regression using rushing and passing efficiency (including sack yards) to estimate rushing TDs. Interceptions are a big part of the passing game--teams that throw a lot of INTs would be expected to limit their opportunities for rushing TDs. So I'll include interception efficiency in the model. I'll also use standardized variables so we can directly compare the relative importance of each variable. Based on data from the '02-'06 seasons, the regression produces the following results:
VARIABLE | COEFFICIENT | STDERROR | T STAT | P-VALUE |
const | 13.51 | 0.35 | 38.88 | 0.00 |
Z RUN AVG* | 2.56 | 0.35 | 7.27 | 0.00 |
Z PASS EFF* | 2.16 | 0.39 | 5.54 | 0.00 |
Z INT RATE | -0.34 | 0.39 | -0.88 | 0.38 |
R-squared | 0.42 |
The coefficient of RUN AVG (yds/rush) is 2.56 while the coefficent of PASS EFF (yds/att) is 2.16, which tells us that a good passing game is almost as important as a good running game in producing rushing TDs.
But if we consider the importance of INT RATE (INTs/att), we see that the importance of the passing game nearly equals that of the running game in producing rushing TDs (2.56 vs. 2.50).
So if other teams in your league have already picked up Stephen Jackson and Larry Johnson, or if you're looking for a #3 RB to fill the gap when LT has a bye in week 7, then look for an overlooked RB on a team with a decent passing game.