Calculating "POINTS ADDED"

The points added matrix shows how QBs performed across QB Support Levels, not just in terms of wins and losses, but also in terms of margin of victory.

                            WINS                                  LOSSES

			21	14	7	3		-3	-4	-8	-15	-22
QB SUPPT		22+	15	8	4	1		-1	-7	-14	-21
0.5 or Lower		1.000	1.000	1.000	1.000	1.000		0.897	0.846	0.667	0.513	0.000
0.5 to 1.499		1.000	1.000	1.000	0.969	0.922		0.813	0.656	0.438	0.234	0.000
1.5 to 2.499		1.000	1.000	0.948	0.885	0.688		0.479	0.313	0.156	0.052	0.000
2.5 to 3.499		0.990	0.941	0.833	0.696	0.529		0.441	0.245	0.127	0.029	0.000
3.5 to 3.999		1.000	0.944	0.778	0.611	0.417		0.250	0.139	0.056	0.000	0.000
4.0 to 4.999		0.939	0.864	0.576	0.348	0.227		0.076	0.030	0.000	0.000	0.000
5.0 to 5.999		0.717	0.417	0.300	0.133	0.067		0.017	0.000	0.000	0.000	0.000
6.0 or higher		0.533	0.311	0.222	0.089	0.044		0.044	0.000	0.000	0.000	0.000

	NO QBs SCORED HERE			Better than 30 - 50 %  %
	Better than 90% +			Better than 20 - 30 %
	Better than 75 - 89 %			Better than 10 - 20 %
	Better than 60 - 74 %			Better than   0 - 10 %
	Better than 50 - 60 %			Worst Performers

For each game, a QB receives a QB Support level. Additionally, each game is won or lost by a specific amount. By looking at those two variables, the above matrix can place each QB’s game in a cell. The number in that cell represents the percent of QB Performances (1) in that QB Support range and (2) that yielded a worse result (a result to the right of that cell). The number in that cell is then the QBs “Points Added” score for that individual performance.

WHAT ARE THESE PRETTY COLORS TELLING US?

These colors are telling us that QB Support has significant effect on a team’s outcome. As we increase in QB Support (going down the Table), we see that it’s increasingly more common for QBs to win, and win by larger margins. The diagonal shifting of those yellow and light green cells show the results average QB performances secure for a team given different support levels.

WHY THESE CUTOFFS?

            In “Wins Added,” I talked about the ranges of QB Support that I use. But why the cutoffs for the Point ranges. Well, I think the closest games are those decided by a field goal or less. I include in this category any games that go to overtime (tied at regulation). I think it makes a big difference if you need just a FG or a TD to tie or take the lead. After that, I think the biggest difference is whether it’s a one score, two score, or three score game. I did not take two point conversions into account, and I could say more on the topic, but I won’t right here.

            After being up three scores, I feel like much of the difference lies in a team’s approach rather the performance of the QB.  It doesn’t make sense in my mind to put much value on winning (or losing) by 38 points instead of 31 points. The game is out of reach for your opponent (or you) one way or the other and some coaches may put in back-ups while others may try to run up the score.

WHY IS “POINTS ADDED” HELPFUL

Points added is helpful because it gives a more complete picture of the game than “Wins Added.” If a QB Wins with a QB Support level of 4.5, that tells us that he performed better than 23 percent of QBs who lost with a QB Support level in the 4-5 range. If he won by 17 points or 3 points, we know that he either outperformed only those 23 percent who lost or the 86 percent who either lost or won by a smaller margin.

Matt Ryan’s 4 point win over the Cardinals earlier this year might have been his worst game. He squeaked out a win only because the rest of his team put him in a great position to do so. “Wins Added” gives Ryan the same 0.067 for that game that Tom Brady received for a very strong performance against the Rams in a 45-7 blowout. In contrast, “Points Added” gives Ryan a score of .133 for that game and Brady a score .717 for the Rams game.

WHY IS “POINTS ADDED” PROBLEMATIC?

While “Wins Added” places too much emphasis on who won or lost, “Points Added” doesn’t place enough. Consider these two scenarios where QBs received QB Support of 2.75. In scenario 1, the QB, down 30-20 throws a 25 yard TD pass on the final play of the game. His “Wins Added” score stays the same (-.47), but his points added goes up by 0.314. In Scenario 2, the QB is down 30-26, and throws a 25 yard TD pass on the final play of the game. This time, it is no meaningless play. This time, it’s the game-winner. And yet, the QB’s “Points Added” in scenario 2 go up by .288.

There are number of similar scenarios. Not all points are created equal. Pulling within 7 or even 3 points is simply not as valuable as scoring the go-ahead touchdown. “Points Added” corrects some of the problems of “Wins Added,” but it also has its own problems.