SUMIF On A Difference?

I have a spreadsheet that records a bunch of golfer's scores for a round of golf.
I have a range G10:X10 that shows Par for each of the 18 holes.
I have many rows below that, G11:X11 is one example, that are individual golfer's scores.

I'd like to add a column, say in column AC, that would count the number of birdies each golfer had in the round.

Thus, I was thinking something like this in AC11:
=SUMIF(G11:X11 - G10:X10,"=-1").

Of course that doesn't work. I need some way of creating a range of 18 differences for the first parameter of the SUMIF function. I know that I can write a VBA macro for it or add another row for each golfer with the difference (but that would double the size of the spreadsheet). Is there an elegant way to do this with a worksheet function given just the scores and par for all 18 holes.