Perl 5 -p
-Minteger
, 77, 73 bytes
/ (.*) (.*) /;$_=($`-$2)*($1-$')>=(($`+$1)/5+($2+$')/5)%2*($`-$1)*($2-$')
2 bytes saved using xnor approach, and 2 other bytes using integer division, explanation is (renaming: $` -> a, $1 -> b, $2 -> c, $' -> d), first answer was:
(a-B)(b-A)>=0
if scores are in reversed order ((a+b)/5%2^(A+B)/5%2==1
)(a-A)(b-B)>=0
otherwise
as (a-B)(b-A)>=0
is equivalent to (a-A)(b-B)>=(a-b)(A-B)
(a-B)*(b-A)>=0
<=>ab+AB-aA-bB>=0
<=>ab+AB-aB-Ab>=aA+bB-aB-bA
<=>(a-A)(b-B)>=(a-b)(A-B)
answer can be
(a-A)(b-B)>=0
if(a+b)/5%2^(A+B)/5%2==1
(a-A)(b-B)>=(a-b)(A-B)
if(a+b)/5%2^(A+B)/5%2==0
or
(a-A)(b-B)>=(a-b)(A-B)*((a+b)/5%2^(A+B)/5%2)
or with integer division
(a-A)(b-B)>=(a-b)(A-B)*((a+b)/5+(A+B)/5)%2