You guys who feel like not all TDs are equal, you believe 4th Q TDs >>> 1st Q TDs, "clutch" is all that matters, etc...Total QBR is the stat FOR YOU, it was made for you.
ESPN saw people complaining that passer rating didn't account for 'clutch' moments, nor did it account for rushing...so what ESPN did was create a stat that puts all the emphasis on TDs/yards/INTs scored late in games when the score is close.
The final major step is to look at how "clutch" the situation was when creating expected points. A normal play has a clutch index of 1.0. For instance, first-and-goal from the 10-yard line in a tie game at the start of the second quarter has a clutch index of almost exactly 1.0. A more clutch situation, one late in the game when the game is close -- the same situation as above but midway through the fourth quarter, for example -- has a clutch index of about 2.0. Maximum clutch indices are about 3.0, and minimum indices are about 0.3.
These clutch index values came from an analysis of how different situations affect a game's win probability on average. One way to think of it is in terms of pressure. A clutch play is defined before the play by how close the game appears to be. Down four points with three seconds to go and facing third-and-goal from the 3-yard line -- that is a high-pressure and high-clutch index situation because the play can realistically raise the odds of winning to almost 100 percent or bring them down from about 40 percent to almost zero percent. The same situation from midfield isn't as high pressure because it's very unlikely that the team will pull out the victory. Sure, a Hail Mary can pull the game out, but if it doesn't work, the team didn't fail on that play so much as it failed before then. On third-and-goal from the 3-yard line, failure means people will be talking about that final play and what went wrong.
The clutch indices are multiplied by the quarterback's expected points on plays when the QB had a significant contribution, then divided by the sum of the clutch indices and multiplied by 100 to get a clutch-valued expected points added per 100 plays.
read the bold
minimum situations are worth 0.3
maximum is worth 3.0
That means a TD scored late in the 4th is worth 10x more than a TD early in the 1st.