So they could fit five matches in a four hour time slot. They also had a "bleed" time to complete the matches if necessary, which happened on two nights of the four. The Matchroom people have learned that by adding just one additional game to the match can add 10-15 minutes to the match time; five out of nine games as opposed to six out of eleven. In the past they often ran out of time and had to cancel the last match of the evening. In those cases, they were forced to shorten matches played the next day. Better to make the change going in and not after the fact. Hope that makes sense to you.