In the game of duplicate bridge, the idea is to get a better score than the other pairs who, during the course of the session, play the same hands at different tables. A pair will get one point for every score they beat, and half a point for every score they tie.

One particular hand was played eight times. All pairs playing North-South scored either +420 or +450. (The derivation of these scores doesn’t matter, although they are common and result from a contract of, say four hearts.)

One of the pairs that scored +420 noted that this score was worth 2.5 points at the end of the session.

How many points would this pair have received had they scored +450 instead?