For the Ryder Cup, +1/2 point could be a huge difference if you bet the US to retain the Cup, but we are betting that the Euros WIN the CUP and therefore they must win by 1 point 14.5 to 13.5 minimum....at 14-14 the Euros do not win the Cup....so +1/2 -230 is a a sucker bet and the only reason you would need it is, if there is a tie, however you must have noticed you can get 12-1 on the Tie. (you could back up your Euro bet with 12-1 on the Tie, but I think it is throwing money away, the Euros should win on home soil and the line should be -200.)
Laying -2.5 +145 is trying to save vig, and the sportsbooks are saying 1/2 point is therefore worth 23 cents??? There is no value on half a point in this match on the Euros IMO. This prop could be compared to index betting, which is a very difficult process to win consistently on. Or you could say this is a prop bet like Green Bay -7 +200 on MNF...another sucker bet.