diff --git a/src/lib/game.rs b/src/lib/game.rs
index a24da08..f01fdf8 100644
--- a/src/lib/game.rs
+++ b/src/lib/game.rs
@@ -226,8 +226,9 @@ impl<'g> Displacement<'g> {
 	}
 }
 
-fn would_overflow(n: usize, d: isize, max: usize) -> bool {
-	let too_little = n == 0 && d == -1;
-	let too_big = n == max && d == 1;
+/// determine if the given number, added a delta that is either 1 or -1 to it would overflow a certain maximum value for n
+fn would_overflow(number: usize, delta: isize, max: usize) -> bool {
+	let too_little = number == 0 && delta == -1;
+	let too_big = number == max && delta == 1;
 	too_little || too_big
 }