I didn't watch the superbowl yesterday but I heard how Tom Brady and the Patriots eeked out an OT win. I remember when they were down in the first 3 quarters I told my friend - don't get too excited, you can never count out Tom Brady.
What's interesting about Brady, and other great athletes like Serena Williams, LeBron James, Roger Federer, and Conor McGregor, is there ability to rise to the occasion. When the chips are down or the pressure increases, they will not fold. In fact, you could probably say they like the pressure and thrive in it.
Greatness is also the ability to win in multiple contexts. Whether it's across different Opens, NBA games with different opponents, or NFL games under various weather conditions, great athletes just win. There are no excuses of tiredness or adverse conditions or other externalities - they just win.
Greatness is a function of the devotion of total self into a mission. Without putting your all, you cannot achieve greatness. Without acting as if this is a life or death battle, you will not go that final inch to make the catch, or the stretch for the ball, or stand up when someone just knocked you down. You will not achieve greatness.