In Week 16 at East Rutherford, Ken Roczen blew away the Supercross field, and as impressive as that win was, he seemed even better the week before. To my eyes, it looked like his win in Week 15 at Foxborough could have been the most dominant win of the 2016 season. Since the only remaining race, in Las Vegas, will not have any consequence for 1st or 2nd place, I think it's safe to say that whoever wins it won't be considered a "dominant" one -- meaning we can look at weeks 1 through 16 to judge who had the most dominant win of the 2016 Supercross 450 season.
Most Dominant Win from 2016 450 Supercross?
One way to view the magnitude of a win is to look at how many riders were lapped by the leader. The two races with the most lapped riders were actually won by Ryan Dungey, while Ken Roczen's best comes in third:
Roczen lapped 13 riders at Foxborough, and Dungey actually bests that by 3 at Indy and by 2 at Santa Clara.
You'll notice that the average lap time is included because it might affect how difficult it is to lap the other riders. I'm not totally sure that's true because although the shorter laps means it's easier to catch the riders who are being lapped, there is also less time overall in the race to lap them. But, the overall trend is that races with shorter laps also had more lapped riders. To take that into account, this list below is sorted by a measure that incorporates the number of riders lapped AND the amount of time it took to lap them ("+" signifies that it is comparing to the average where "1" is average, so "2" would be twice as much as average, and ".75" would mean 75% as much as average). Also listed is the number of laps that the lapped riders lost to the leader (as in, if Jeff Alessi only finished 17 laps, then that would count for 3 "lapped laps").
In this scenario, Roczen's Week 15 win at Foxborough stands out at #1, just ahead of Dungey's win at Anaheim 2. Dungey's 16 lapped riders at Indy is listed third.
Another way to view "dominance" is to look at how many seconds the leader was ahead of second place. In this case, Roczen absolutely ran away from everyone in the last two weeks:
One problem with that, though, is the leader may ride cautiously (same for the second place rider) after a big enough lead has been established, so the final result in terms of seconds ahead of the next-closest rider may be somewhat artificial. Another way to look at it is their average lap times over laps 2 through 18 -- leaving out the final two laps where the cruise control might kick in (it could be earlier, but two laps before the end is a reasonable cushion). Lap 1 times are excluded because they aren't part of the AMA published data.
Average lap of winner vs 2nd place:
(Keep in mind that in Detroit, although the official results have Anderson #1 and Musquin #2, Dungey actually crossed the line first. Technically the winner or not, Dungey's average over laps 2 through 18 was 0.29 seconds faster than Anderson.)
Again, Roczen's victory in Week 16 is the most impressive. Surprisingly, Anderson's win in Week 1 comes in at a relatively close second. Then a major dropoff to Dungey's win at Oakland, with several races grouped relatively closely after that.
For the two or three readers who made it this far through the technical mumbo jumbo, there's one more way (even more technical) to look at overall performance relative to the rest of the field, which is the Z-Score. It measures how much better (or worse) than average the rider was in the race, but also standardizes this by taking into account the full range of performance of the entire field, which also normalizes the length of the race. (This is done by dividing by the standard deviation of the average lap times of the entire field for the race. Bill Barnwell explains it much better than I can).
When we look at the winner's Z-Score from each race (again just at laps 2 through 18), a new race comes out in the #1 spot, but there are several bunched around the top without much separation:
The first three in this list of Z-Scores have been around the top in the other perspectives. But what I think is interesting are the Z-Scores of Tomac at Daytona and Roczen at Foxborough.
For Daytona, Tomac didn't lap many riders (#11 in Table 1), but he did look better according to Table 2 (#4) which took into account the length of the race; since Tomac wasn't that far ahead of Dungey, he didn't rank very well in Table 3 (#10) or Table 4 (#13). But if you compare Tomac to the entire field of riders at Daytona, Tomac's win is back at #4 since Z-Score normalizes (or at least should) for the length of the race.
Roczen's win at Foxborough had the third most lapped riders and the most "lapped seconds". Roczen had the 2nd largest lead over second place for the full race, and the 4th largest lead over the second place rider in laps 2 through 18. However, the Z-Score didn't see that win as very impressive (#11), likely because of some combination of two factors -- (1) a few riders had very bad races (such as Catanazaro and Schmidt), which brought the average down but also increased the standard deviation, and (2) many of the other top finishers were above average (in this case, there were 5 riders who were 3 seconds or better than average, and another 4 who were 2 seconds better than average), which dilutes the how impressive Roczen's win looks, at least in terms of relating it to the entire field.
All that said, I think the two most dominant wins of the season were Roczen at East Rutherford in Week 16 (somewhat expected) and Dungey at Oakland in Week 4 (totally unexpected). Neither did that well in terms of lapped riders, but in both cases, the winner handily beat the 2nd place rider AND did well against the entire field. From there I think it's a dead heat between those two wins. If I'm putting more weight on how well the winner did compared to the entire field, I go with Dungey at Oakland. If I care more about how much the winner beat the 2nd place rider by, I go with Roczen at East Rutherford. If I absolutely have to call it, it would come down to not having to type "East Rutherford" any more times since that appellation (thank you Thesaurus) is long, harsh, and not exactly pleasing to the eyes….