Race ski boots can fit very tight and can be tough to decipher if they are too small or simply need to be broken in by use. A great way to determine a correct fit in a tight fitting race boot is shell fitting. Once you have received your ski boots, and before you begin trying them on, remove the liner from the shell by unbuckling the boot fully and pulling on the back cuff of the liner until it slides out of the shell. Next, put your foot in the boot's shell and push your toes up until they touch the front of the boot. Then look to see how much space is between your heel and the back of the boot. Recreational skiers are looking for 1/2 to 3/4 of an inch of space, racers and very high performance skiers who like a very tight fit are going to want even less. If you have more than that, you probably have a boot that is too large. This process, known as shell fitting, is another good way to make sure you will have the correct size boot before hitting the slopes.