[Rusty]

Thanks for pointing out the exact location.
Here, the O should be a G. If you hover over the O on the opposite side of the page, in the Posiciones Completas display, you'll see that a G appears. And if you click on the Posiciones Completas link in that display, you'll see that a G is used where expected as a column header.
Hovering over the G on the Posiciones page, you'll see El número de partidos ganados.
In the Glosario at the bottom of the page, the same information is given.

I don't know why O was used on the page you pointed out, since everywhere else it is a G or a V. Until led to believe otherwise, I think you've happened on a programmer error.

I also see that the programmer chose to use Derrotas for the P (clearly, Perdidos, or El número de partidos perdidos, should be the other half of the wins/losses pair). However, Victorias/Derrotas can also be used (and I did find a page that uses the letter V for Wins).