I’ve been banging on for a while about a rise in the weights not being an impediment to a horse winning, and I’ve said it with such confidence that it’s almost a mantra. But is it true?

Yeah, of course it is. Fact. Look.

So, like, it’s a fact. Case closed. But let’s hone in on that magic zone between 4lbs and 7lbs heavier, because this is a regular feature of any racing season, and we need to understand a little more about the scenarios we encounter, and whether the figures still stack up.

2-year-old Flat / All-Weather Stats

I’ve picked this scenario because 2-year-olds are reliable creatures and tend to run according to their ability. This is a little bit of a mish-mash but generally non-handicaps on the flat are maidens and we’ve got 2-year-old horses that have excelled in their previous race and have been given 6lbs or 7lbs extra to carry because they need holding back against their unraced rivals.

Take a look at this:

I extended out the data set here to give you an idea of the spectrum of weight differences between the horse’s current race and its previous race. As you can see, if weight is taken off in a flat non-handicap race, then the win rate improves a tiny bit to around 12.5% for 2lbs lighter, but if weight is added – right up to 7lbs, then your win rate gets up to a much healthier 18%.

That’s before you even start rating the horse itself.

OK, so that’s flat non-handicaps, and we’re fine with that, we’ll keep an eye out for those horses who have been hiked in the weights and assess whether we think they’ll progress or not. But what about them messy handicaps?

It’s almost as if the weight has to be hiked a sufficient amount – 6lb or 7lb for it to take effect, and the most you want taken off a horse’s weight is around 3lbs. Anything lighter than that, and the win rate shrinks enormously.

OK, so we’ve looked at 2-year-olds, and that’s fine because a 2-year-old runs more or less as it should do. They’re like toddlers.

If we focus on three-year-olds, who can start to develop their own characteristics, the curve flattens a little:


  • 5lbs heavier = 13.2% win chance
  • 6lbs heavier = 12.58% win chance
  • 3lbs lighter = 10% win chance

But Non-Handicaps

  • 6lbs heavier = 14.9% win chance
  • 7lbs heavier = 15.76% win chance
  • 3lbs lighter = 12.8% win chance

So there it is – if you’re thinking of backing a horse in a non-handicap especially, and it has been raised 6lb or 7lb, then statistically speaking, you have a better chance than backing a horse that has been kept at the same weight, or has had a pound or two shaved off.

I’m not going to end there. There has to be something else that can help us get an edge.

Let’s look at the number of days since the horse last ran in flat races, with a 6lb or 7lb rise in the weights (irrespective of age now)

  • 11-15 days ago: 13.2% win rate
  • 16-20 days ago: 18.7% win rate
  • 20-25 days ago: 19.6% win rate
  • 26-30 days ago: 15.2% win rate

So there’s clearly a ‘golden period’ in which a horse is raced – and we’ve applied that to a number of our flat racing algorithms anyway. It’s partly true of the National Hunt, although you could extend the period downwards a little in that case.

Let’s then look at where the horse finished in its last race, also in flat races with a 6lb or 7lb rise in the weights, irrespective of weight

  • 1st: 29.23% win rate
  • 2nd: 24.56% win rate
  • 3rd: 12.5% win rate

Obviously the data stacks up significantly towards horses that won their previous race (758 races vs 250 for 2nd and 250 for 3rd). Because why else would they have received a further 6 or 7 pounds?

The Sucker Punch

But here’s the absolute sucker punch. The piece of data that really makes you think, and perhaps we should have thought about it all along.

  • Males: 17.25% win rate
  • Females: 11.82% win rate

Anyone got a reason for that? I’ve often said that fillies tend to come into their own late in the season, as opposed to the colts who are often ready and raring to go from the off. It’s usually by late August / September that the fillies start beating the colts (another piece of data I’m being anecdotal about), so would this be a factor? I literally have no idea.

And so I’ll leave you stumped on that one – but here’s the takeaway:

  • A rise in weights only improves the horse’s chances of winning
  • But that’s usually because it’s a good horse – most of them won their previous race
  • There’s a golden period in which to back these horses, at least on the flat
  • The numbers are more stark with two-year-olds, but still effective with three-year-olds
  • This applies to males, and not fillies/mares