More on Rowing Well For Boat Speed

I came across a blog entry on Coach Thrasher that led me to a short analysis that provides some underpinning for the technique vs. erg discussion that the Pitt four's HOCR performance engendered. Of course, there are many factors that go into technique and no single factor is totally predictive, but this timing analysis provides one piece of the technique puzzle.

The charts relate to the oar pressure of rowers in a four. In "Coach Thrasher's" words, the underlying idea is that

"the force applied to the boat is the SUM of everyone rowing. If we can sum the peak-power for each rower at the same point in time, we'll get the MAXIMUM force applied to the water to move the boat forward the fastest. The higher this maximum force, the faster the boat will go, but the maximum force is the sum of everyone's efforts, so it's important to time it well. (Obviously there are many factors that contribute to boat speed as well, but this force-timing is really important in small boats.)"

"Note an important aspect of this: the boat will go faster by having the best timing, not by hammering the oar through the water! So a weaker crew with better timing will go faster than a stronger yet sloppy crew."

Now, take a look at the graphs. The difference is obvious, but at first may not seem terribly huge. We're told, however, that the better crew is going about 0.3 m/s faster, which works out to about 30 seconds over a 2000m course. Next, think about all the lightweight fours rowing over nearly 5000 meters at the HOCR. If Pitt's power application curve looked like that of the best crew in this analysis, and everyone else looked like the worst (not impossible), it would take a mighty strong crew to hammer the oar through the water hard enough to beat them.

This sort of thing can be difficult to see by the untrained observer, but that is why we have coaches and not personal trainers. As the Peach web site says, "A coach can identify these differences in terms of body movement, posture, sequencing of legs, trunk and arms during the drive etc."

There are a zillion other factors at play here, of course, and I have no idea if Pitt's advantage was power application timing. It may have been something else. For example, even within power application, the moment of maximum application is important too. The point is that seemingly small differences in technique and timing can make large differences in boat speed.

Winning the Ones That Matter

Matthew Pinsent had an article in The Times last week in which he talked about the Searle Brothers. According to Pinsent, the Searles "used to race for a full season, which entailed half a dozen regattas each summer in the build-up to the World Championships or, once every four years, the Olympic Games, and yet their sum total of medals and victories from these build-up races is outnumbered by their world and Olympic medals almost two to one." They won when it mattered.

We all want to win every race we enter, but not all races are created equal. Early season races are less important than late season, and as prestigious as it would be to win the Head of the Charles, I'd rather win IRAs. The Searle Brothers understood that and, more recently, so have the notoriously slow starting Wisconsin Badgers. In fact, a quick look at recent history shows that rarely has the eventual national champion been a dominant force throughout the season.

There's been a pretty strong correlation between Sprints winners and IRA winners as in the nine years since 1998 the Sprints champion has won IRAs six times. If we go earlier in the season to the Knecht Cup, however, the relationship isn't as strong. The fast IRA boats have been racing at Knecht since 2001 so if we look at the six years since 2001, the Knecht champion has won IRAs only twice. In those six years only one crew (Princeton) has won all three regattas. In fact, only that one crew has won both Knecht and Sprints. In it's three national championship seasons, Wisconsin has been third at Knecht twice, and second once. Knecht seems to be a particularly bad predictor of the eventual national champion.

Dodd to Lead Buckeyes

The Ohio State Lightweights also have a new head coach after Peter Steenstra moved on to coach at Cornell. Hugh Dodd, takes over a lightweight women's program that has worked its way onto the national scene and has won the ECAC title. There is a lot of upside for Coach Dodd to exploit. Dodd, formerly the men's freshmen coach, will be head coach for both the men and lightweight women.

Interestingly enough, Coach Dodd rowed at the University of Washington, the same alma mater as Wisconsin's new coach, Erik Miller. [Update: I originally thought that the two coaches were teammates but as a result of some paperwork requirements and other red tape Coach Dodd's official graduation date is out of kilter with his actual rowing dates. They missed being teammates by three years or so.]

Racing is Starting in Earnest

The races are coming fast and furious now and, as usual, it's hard to tell which have lightweight events. Several will probably have light four or eight events, and UCF will be racing (again) in Florida. Ohio State is scheduled to race Purdue and it would be nice to see a lightweight eight race there. I don't know if one is scheduled but those two teams have put out some good light eights in recent years so it would be great to see them both carry on. OSU will have a boat if Purdue does. Meanwhile in Philadelphia, the Princeton lightweight frosh are scheduled to race in the heavyweight freshmen eight race at the Murphy Cup.

Dad Vail Fours vs. Eights

A reader posted a comment to a post on dedicated lightweight programs suggesting that the real race at Dad Vails is lightweight fours because that event has more competitors than lightweight eights. This comment was followed by another taking issue with that statement, saying that the light eight winner was closer in speed to the open 8 winner than was the light 4 winner to the open 4 winner.

Both are correct in their facts. There were 18 light four entries vs. just 5 in the light 8, but the light 4 was 3.3% slower than the heavy 4 while the light 8 was only 2.5% slower than the heavy 8. To try to understand what this means, we need to look for some context. We can get that by looking at other races. At Eastern Sprints the light 8 was 5.1% slower and the light 4 was 2.3% slower - the opposite of Vails! IRAs don't work because the heavies row in a different regatta and no fours are raced at IRAs. (Rowing in a different regatta means that times are not at all comparable, but what the heck, I'll do it anyway. The light 8 turns out to be 5.0% slower - a result I attribute to pure coincidence.) I've used 2005 results here, as opposed to going back and doing some sort of averaging over the years.

We've just succeeded in muddying the waters so now let's look at world records. I know they were all set at different times and on different courses, but as world records we can use them as measures because to set a world record the boats will have met up with generally the same conditions. No light eights or light fours race internationally so we'll use doubles and quads as proxies. Here we find that light quads are 5.1% slower and light doubles are 2.8% slower, the same pattern as Sprints. The men, by the way, also follow that pattern at Vails and in the world records (no fours at Sprints).

So, this suggests that the fact that at Vails the light eights are closer to the heavies than the light fours are is an aberration. I'm not sure why this is but I'll guess that it's because the heavyweights in Dad Vail programs are closer in size to lightweights than in the scholarship and national team programs. I think this supports the point I made earlier that if Dad Vail programs would concentrate on lightweights they can be much more successful on a national (as opposed to the Dad Vail) level. Think about the Truthtellers.

Back to the original question about which event is more competitive at Vails - I don't know. I think we can safely say that despite only having 5 entrants, the light 8 is as competitive as any other event. We don't know, however, if they're closer to the heavies because the heavies are slower or the lights are faster. As for the fours, they do seem to be a bit slower than they should be, but still close enough to be in the ballpark.

The other thing that comes out of this is the fact that the men are generally closer to their heavyweight counterparts than the women (except for the light eight at Vails). This probably is due to longer standing and better developed lightweight programs for the men. The good news for the light women is that they can look forward to improving their speed at a faster rate than the heavies.