These spreads are more for fun, its not a science, its an art. Now we do know Coppermine beat HG by 2 in the fall.
Coppermine also beat M&D by 3, while HG beat them by 1.
HG beat Aces by 5, Coppermine beat them by 8.
Eagle Stix beat Coppermine by 2, Eagle Stix beat HG by 4.
All the above, you can justify Coppermine being a few goals better than HG. If you disagree, I'd like to hear the rationale. Now -4.5, that a little high but call it a hunch.
If you're basing it on similar opponents in the fall, sure this makes sense (though 4.5 is a little high). There is something to be said about how teams match up against each other, though. Also, I think the teams you see this spring will look a little different than the fall when people are just trying things out and trying to make up for soccer/field hockey absences. If both teams put their best team on the field for this game, which they presumably will - I think you'll probably see a close game like you did in the fall and it's one that could go either way.
