Sorry to be so late to answer; Hey, it's the weekend.
If you want to be able to enter the score as "189-5x", here is a formula to convert that to 189.05 automagically:
The input is in B1.
=VALUE(LEFT(B1,FIND("-",B1)-1)&IF((LEN(B1)-FIND("-",B1)-1)>1,".",".0")&MID(B1,FIND("-",B1)+1,LEN(B1)-FIND("-",B1)-1))
I you want to convert that number back to 189-5x format, this is the formula:
The value to convert is in c1:
=TEXT(INT(C1),"####")&"-"&TEXT((C1-INT(C1))*100,"##")&"X"
Of course, you can get fancier and have the formula accept 189-5X or 189.05.
The input value is in B2:
=IF(ISNUMBER(B2),B2,VALUE(LEFT(B2,FIND("-",B2)-1)&IF((LEN(B2)-FIND("-",B2)-1)>1,".",".0")&MID(B2,FIND("-",B2)+1,LEN(B2)-FIND("-",B2)-1)))
Here is a little spreadsheet with the formula. Just change the values in b1 or b2.
I suggest you keep the scores in nnn.nn format as it makes it a lot easier to keep track, add up and so on. If you store it in nnn-nnX, it would be like doing accounting in Roman numerals.