Expert Blog

Wednesday, December 30, 2009

Revisiting team ranking schemes

What must be the criteria to accurately define a team’s standing in world cricket? Our expert looks at existing schemes and analyses them

I know of a lot of team ranking schemes in cricket: some are mighty complicated, and many are duds.

It’s quite a puzzle actually. A lot of people can recognize a good team performance in cricket, but few seem able to encapsulate it in an appropriate mathematical model.

Let’s look at ODI cricket, and let’s list some of the popularly touted criteria, in no particular order:


1. If you win more matches, your ranking should be higher

2. If you defeat stronger teams, you must get more weight

3. If you win ‘away’ matches, you must get more weight

4. Recent wins must get more weight, and this weight must steadily decline over time

5. Winning by bigger margins must fetch more credit

6. Winning a series or tournament must fetch extra credit

7. Winning when your top players are injured must receive more recognition.


About half of the existing ranking schemes only consider criterion 1. They give one point for a win, 0.5 for a draw or tie, and 0 points for a loss. Then they choose a time window (typically a calendar year or a moving 12-month window) and start calculating!

It’s easy to pick holes with this scheme: play 20 matches with the weakest available team and win all of them! So if Bangladesh plays 20 ODIs against Zimbabwe and wins all of them, Bangladesh could become the ‘best’ team in the world.

This isn’t making much sense. In fact, it’s pretty clear that a ‘good’ ranking scheme must use as many of the above criteria as possible.

How many of these criteria are feasible? Most would say criterion 7 is subjective. They might also argue that criterion 5 is a little hard to model.

Let’s therefore look at ICC’s ODI ranking scheme (that we’ve written about earlier). It considers criteria 1, 2 and 4. In particular, the ICC scheme models criteria 2 and 4 rather elegantly. I won’t go into details, but criterion 2 is handled really neatly. My only grouse with criterion 4 is the choice of August 1 as the cut-off date to reduce weights: this makes a win on August 2 relatively more valuable than a win on July 29.

The ICC scheme can, in an awkward sort of way, accommodate criterion 6 (the ICC Test cricket ranking scheme does consider criterion 6; the awkwardness in the ODI ranking scheme is because of tournaments involving several teams). It also seems feasible to bring in criterion 5 via the Duckworth-Lewis method, because D/L can quantify every ODI win in terms of a run margin.

The inability to accommodate criterion 3 is a serious weakness although it can be argued that the ‘home-away’ variation is less pronounced in a 50-over match, especially with pitches everywhere now being prepared to favour batsmen.

The ODI ranking scheme published on rediff.com for 8 years is of comparable pedigree: it accommodates criteria 1, 2, 3 and 6, but fails to consider criterion 4, although there is a reasonably easy way to do it.

There is, of course, a completely different way to look at team rankings: suitably add up the individual rankings of the players making up the team! This is the Castrol way, and it was very encouraging to note that the Castrol Index correctly spotted the semi-finalists in the recently concluded Champions League.

http://www.castrolcricket.com/ee/index.php/castrol_weblog/comments/revisiting_team_ranking_schemes/

Tuesday, December 29, 2009

Series in retrospect

Harsha Bhogle shares his thoughts on the Kotla fiasco and on the India-Sri Lanka ODI series that just concluded.

When we were doing the Champions League in October, it was clear that the surface at the Kotla wasn’t conducive to good cricket but we also knew that much could happen, if accompanied by intent, in two months. Obviously that has not happened and whichever way you look at it, this is reason for embarrassment but also an occasion for stock taking. Delhi has not been a particularly distinguished cricket association for a long time now and it has to get its house in order.

Intriguingly, it is also producing the best cricketers for India at the moment. Sehwag, Gambhir, Kohli, Ishant, Amit Mishra, and Nehra makes it six from there in the national side; and with Shikhar Dhawan in good form, there must be something about the city. Maybe they just learn to live with uncertainty and chaos and so become very good at seizing the opportunity that comes their way. Maybe the system creates disillusionment and allows only the strongest to come through and so young men coming out of the system are ready!

And so we either produce pitches that give bowlers no chance at all or come up with something like this!! It suggests to me that we tend to be enamoured by what is in the public eye and not care too much for other critical areas. And so pitch development, or junior cricket will go under the scanner.

It also meant India won the series comfortably and that was appropriate. They were the better team, more rounded and seemed to have the better bench strength. Sri Lanka have tough decisions to take with Jayasuriya and a replacement for the evergreen Murali. I suspect they are missing Chaminda Vaas too and while there are some impressive seamers around they are not as consistent. Consistency is a genuine indicator of class and they are struggling a bit there.

http://www.castrolcricket.com/ee/index.php/castrol_weblog/comments/series_in_retrospect/