Inconsistent APS with LiteRumble

Quoted from APS:

The server calculates APS for each bot by:

1. taking the average percentage score of all battles against each opponent separately to get an APS for each pairing,
2. then averaging all pairing scores to obtain the final average.

Formally, it's

mean(challenger_score / total_score)

for each pairing.

LiteRumble seems to follow this algorithm.

However, RoboRunner is using:

sum(challenger_score) / sum(total_score)

instead for each pairing.

This causes scores calculated by RoboRunner to be different from LiteRumble.