# [Computer-go] Practical significance?

Wed Nov 28 13:25:14 PST 2012

```  Hi!

On Wed, Nov 28, 2012 at 12:03:36PM -0800, Leandro Marcolino wrote:
> > When you said a "23% difference" did you mean the win-ratio is 61.5:38.5?
>
> Well, basically I mean that in 1000 games, system A1 can win about 300
> games (30%) against B, while A2 can win about 530 games (53%) against B. So
> I calculate a difference of 23% between A1 and A2. As Ingo noted, this
> assumes transitivity, that may not always happen in real life, but as Don
> said, it can be a "good" approximation.... In a more strict interpretation,
> A2 would be 23% better "when playing against B"...

But, say, 5% difference between 48% and 53% is surely different kind
of improvement than 5% difference between 94% and 99% winrate, isn't it?

It's a seductive thing to use directly the values your testing tool
prints out and I've been also long measuring performance difference in
percentages. But converting to Elo points has a distinct advantage here,
since they unfold the percentage space to a linear scale. Percentages

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