I was thinking about the Federer Nadal match and how small differences can completely change a match. A lot of it is the scoring system in tennis with separate sets - one of the things that makes tennis so interesting.
If Federer's first serve doesn't desert him until one game later, he wins the first set 6-3. Of course his serve deserted him and he was broken 3 times and would have lost the next set 0-6. However, he wouldn't have started the 3rd set an early break down and would have won that set 6-4, and would have won the 4th set (which would be equivalent to the 3rd they did play) 6-4. So Federer wins 6-4, 0-6, 6-4, 6-4 (or something like that).
However, if Nadal manages to hold his serve in that long game early in the first set, he wins that set 6-4. Goes on a tear winning the next set 6-2 at worst, and is rolling over Federer and it is a completely different match.
Sometimes one ball being a millimeter in or out can change the match that much.
If Federer's first serve doesn't desert him until one game later, he wins the first set 6-3. Of course his serve deserted him and he was broken 3 times and would have lost the next set 0-6. However, he wouldn't have started the 3rd set an early break down and would have won that set 6-4, and would have won the 4th set (which would be equivalent to the 3rd they did play) 6-4. So Federer wins 6-4, 0-6, 6-4, 6-4 (or something like that).
However, if Nadal manages to hold his serve in that long game early in the first set, he wins that set 6-4. Goes on a tear winning the next set 6-2 at worst, and is rolling over Federer and it is a completely different match.
Sometimes one ball being a millimeter in or out can change the match that much.