The weight of a runner is one of the key drivers and reliable predictors of performance; whether it has evolved over time and weather conditions will impact winning probability.
Weight is a crucial factor to determine the winner of a race. To our knowledge, the actual weight of a dog is not available on the web and is only published at the race track. This is the reason why many punters go to the tracks or find out weight information through a network of informers.
Everyone knows that; so what? At DigiTips we love proving facts with numbers and most importantly, through our research, we want to give the right amount of importance to every parameter in the race. We have established the following findings from our research:
Average speed tends to increase with weight up to an optimal point
Males perform better around 35kg. Being heavier tends to slow them down as they often struggle to overtake competitors due to their size. The optimal weight for females is around 30kg.
These graphs have been obtained by analysing the performance of a high number of greyhounds, grouping them in 70 balanced groups depending on their weight, and charting the average weight of each group and their average speed accordingly.
Weight gain tends to be associated with runners with a lower winning probability. These are often runners who have not exercised much over the previous weeks. Conversely, runners who experienced weight loss performed better. However, a large weight loss tends to signal a runner’s poor health condition.
A runner who has lost 250g over the last 5 races tends to win approximately 0.5% more often than a dog experiencing no change in weight. As can be seen on the graph below a weight loss of more than 400g reduces winning chances by a big margin.
The optimal weight loss is around 200g over 5 races.
The weight loss is defined as the average weight over the last 2 races versus the average weight over the last 5 races.
The optimal weight of a dog depends on weather conditions
Heavier dogs tend to perform better under rain. We set out below the historical winning rates for males in both dry and wet weather conditions. As the graph shows, heavier dogs usually perform better than lighter dogs but rainy weather increases the effect of weight: a 1kg difference increases the winning probability by around 0.2% under rain. This only increases by about 0.05% in normal weather conditions.
The above graph was obtained by merging historical data for males with the rainfall observed at the track during the 12 hours preceding the race.
Short distances favour heavier dogs more than long distances
Heavier dogs will on average perform better than lighter ones but distance matters. Heavier and therefore muscular runners will tend to start the race faster. As such, they will often perform better than lighter ones. The impact of weight reduces on long distance where endurance becomes more important. The below graph shows the average speed for males on different distances (100m – 300m, 300m – 500m, 600m – 800m). The slope is higher on short distances: weight is a more important factor on short distances than it is on long runs. A dog who is 1kg heavier will run around 0.35% faster on 100m – 300m, whilst the speed improvement will be around 0.30% on 600m – 800m.