[sumo] Ama

Pierre Wohlleben Pierre.Wohlleben at gmx.net
Mon Jun 4 14:30:52 EDT 2007

Moti Dichne wrote:
> Kaiopectate! wrote:
> > Let me pause and indulge in some crude and generalized mathematical
> > speculation: Because, in sumo, you either win or lose -- each bout,
> > and each basho -- through time (barring major events such as
> > career-changing injuries), you tend to move to your level of
> > capability; rising at the start, and then peaking and then declining
> > parabolically; but, after the initial rise, your wins and losses tend
> > to even out.  To illustrate my theory, take a look at the chart
> > linked here, which includes career W-L records for current upper
> > division rikishi: http://www.scgroup.com/sumo/stat/ I would generally
> > postulate that, for most rikishi, Wins-minus-Losses increases through
> > the first several basho, but then stabilizes.  (This isn't brilliant,
> > really.)
> > ...
> One thing you have to factor in is Makuuchi records versus alltime 
> records.  Most Non -sanyaku regulars in Makuuchi  have a favorable 
> record overall, but have a losing career record in Makuuchi (24 of 
> them, to be exact, including some surprises..). The older they are, the 
> more years up there, their record tends to deteriorate. On the way up, 
> most of them accumulate a lot of wins.
> ALL 60 foreigners have more career wins than losses and many of them 
> have been stuck in mid-Sandanme for a few years.
> I don't think you can enter career records into this equation. Only 
> Makuuchi records. Then, maybe you'll find what you're looking for!
> As for Ama, he is one of the minority with a +.500 win- loss record in 
> Makuuchi. (125-114-1, to be precise).

Yes, in general it's quite an achievement to have a positive Makuuchi record - usually only Yokozuna, Ozeki and perennial sanyaku like Wakanosato and Kotomitsuki manage to do that in the long run. Nearly everybody else eventually succumbs to the banzuke dynamics (as it's possible to keep your rank with a sub-.500 winning percentage), or to their decline phase on the way out of Makuuchi.

(Stefan Gelow had an interesting post on "anomalous" win-loss records several years ago: http://www.banzuke.com/02-4/msg00698.html )

As far as overall career records go: Getting from mae-zumo to Juryo obviously builds up a win "cushion". I don't have any hard numbers, but from anecdotal evidence it usually amounts to 30-40 more wins than losses. In part this depends on the last basho before promotion, of course - it makes no difference whether you get promoted on a 4-3 or a 7-0, but it's padding your resume by another +6 wins in the latter case. In general, the more time somebody takes to break through to Juryo, the better his debut win-loss differential will be (especially if he has spent lots of time in very high Makushita), but of course the winning percentage will be lower - it's the difference between, say, 70-35 and 125-85, as a crude example.

Getting through Juryo to Makuuchi works the other way around. The fast track (just two or three basho in Juryo) generally improves your record by quite a bit, while taking the scenic route usually doesn't add much. Daimanazuru managed to get from J14 to M16 with a very unimpressive 69-66 record last year, though that's an extreme example. (In fact, between his Juryo debut and his Makuuchi debut he had a *negative* total record: In addition to the 69-66, he had a prior Juryo stint of 11-19 and a Makushita interim of 16-12, for a total of 96-97.)

And then, of course, getting from the bottom of Makuuchi to whatever level you're going to top out at. That's an area I haven't paid much attention to, but I'd estimate it at another +10 to +15 wins over losses for the usual joi-jin fodder. So all in all, those guys will have a career cushion of about +55 to +70 before they hit their ceiling and the banzuke elevator starts nibbling away at their win-loss records.

Absences complicate things even further. As a rule of thumb, kosho-covered absences should be ignored, while those that led to a drop in rank ought to be factored in as losses, or any win-loss comparison will become distorted by them (or more specifically, distorted by the wins earned on the rebound from the injury demotion).

So, anyway, Moti is right that career records are not the most useful way to make a performance projection. Makuuchi records are more suitable to the purpose, and at a minimum I'd say you also need to consider each rikishi's age. As for Ama, I'm not quite on board with the "future Ozeki" idea, but if he can avoid injuries he could well remain a steady sanyaku presence for the foreseeable future. Perhaps not at the Kotomitsuki/Wakanosato level, but somewhere nearer to Akinoshima/Takatoriki. He's just 23 and manages to hang in there already, which is normally a good sign, though his lack of size may prevent him from harnessing the usual level of improvement that rikishi undergo between age 23 and, say, 27.

> > I would speculate that
> > the Wins-minus-Losses of many rikishi, after 120 to 150 bouts, were
> > not so different than their Wins-minus-Losses several hundred bouts
> > later. Roho is now 208-149.  What was his record after 120 bouts? 
> > Kokkai is 248-189.  What was his record after 120 bouts? 

120 bouts is kinda arbitrary, but why not...

Roho: 85-38 through 9 lower divisions basho and 4 sekitori basho (Makuuchi debut at that point), then another 38-22 to bring him to Maegashira 1. Since then he's 95-94-6, or slightly negative with absences counted as losses. Roughly what you'd expect to see after two years spent in the meatgrinder.

Kokkai: 83-39 through 11 lower divisions basho and 3 sekitori basho (getting him to mid-Juryo), then another 48-27 to Maegashira 1. Since then: 120-135, which looks worse than Roho's at first glance but is strongly affected by the last basho where Roho was 10-5 and Kokkai just 3-12. Discounting that, their numbers are pretty much interchangeable.


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