среда, 27 марта 2013 г.

Grand National 2013: Don't duck those with big weights

Neptune Collonges carried 11st6lbs to National glory last year

In his latest blog, Simon Rowlands makes the case for keeping an open mind when it comes to studying the Grand National weights.

My recent myth-busting blog titled "weight does not matter" came to the conclusions that a) it inescapably does, but b) it is a "factor whose effect may be masked by other factors in horseracing". 

Those factors include such things as: the ability of the horses; their suitability to the circumstances in question; the efficiency with which they run their races; and the effects of things like jumping aptitude, draw and so on. Weight should still be a consideration - and may well be the preferred form of expression for these and other factors - but, of itself, it can be rendered of low significance. 

Nowhere is this more likely to be true than in the Grand National, a race over just short of four and a half miles, with 30 unique obstacles, the biggest field size of the year, and a very high incidence of non-completions. 

Ask yourself which you think is more important: the ability/luck to survive, and even thrive, under unique and challenging conditions; or a few pounds extra/less on a horse's back? Even hardcore weight believers are likely to plump for the former. 

Nonetheless, weight carried has been a major consideration in the race for some punters over the years. And by "weight carried" I mean absolute weight, not relative weight. 

Just one winner out of 19 between 1989 and 2008 carried 11 stones or more. Plenty of highly-weighted horses ran well in that period, but they usually came up short against something better treated than them near the foot of the handicap that managed to get round. 

And that was the point. It was not the fact that a horse was carrying 11-00 rather than 10-13 that was preventing it from winning, per se: it was that something of similar ability but carrying less weight was tending to get round and beat it. 

A fixation with absolute weight - as opposed to relative weight - is mistaken, and the absurdity of it can be illustrated by an anecdote from a few years back, when a pundit (who shall remain nameless) bigged up the chances of a number of the horses due to carry less than 11-00 in the Grand National several days ahead. And he shouted from the rooftops when one of those horses, Mon Mome, won the race at 100/1. 

It was only some time after the event that it seemed to dawn on him that the weights had gone up 2 lb and Mon Mome had as a result carried 11-00, which, according to the pundit's original article, meant it simply could not win.  

Absolute weight can change, and so too can the times. The last four Grand National winners have all carried 11-00 or more, perhaps in no small part due to the BHA Handicapper bending over backwards to accommodate better horses in the race. While average weight carried for all runners in the race has increased from 10-06 in 2001 to 10-09 in 2012, the average handicap mark has shot up from 135 to 146 in the same time.

As an aside, it is interesting to note - for those inclined to trot out the "weight counts for more at longer distances" mantra (it does, but so do the ability differences it is meant to be offsetting) - that horses carrying 11-06 or more in handicap chases in the UK in 2012 fared better at longer distances (28 furlongs and more, IV 1.39) than at shorter. 

Measuring performance in the Grand National presents its own unique problems. The extreme test customarily results in more than half of the 40-strong field failing to complete, something which conservatives see as being integral to the race itself. How should we gauge a supposed effect when a large part of the population cancels each other out in this way? 

Percentage of rivals beaten - which is often a good measure - is rendered questionable in such circumstances and an apparently better approach is to place runners into quartiles by weight carried and then to consider impact values (IVs) for first-four finishes (even in its worst year, 2001, The Grand National managed four finishers out of 40 starters).

By this measure, runners in the bottom quarter of the weights (whatever those weights might be) had IVs of 0.58 this century and 0.33 in the last three years; the mid-low quartile had IVs of 1.08 and 1.00; the mid-high quartile had IVs of 1.17 and 1.33; and the top quarter of the weights had IVs of 1.18 and 1.34. 

So, contrary to what seemed to be received wisdom in the past, backing highly-weighted horses in The Grand National should not be seen as an automatic waste of money, and that has applied all the more in recent years. 

But it should be remembered that this is not so much down to the absolute weight a horse is carrying as that weight relative to its rivals. And you still need your horse to get round to capitalise, something which is in the region of 2/1 against judged on Grand Nationals this century.
 
Surviving could well matter more than weight carried to the majority of the runners once again.

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