They use Transponder 24 on SAT 110 for any Sports PPV channel feeds they have to add that they don't already carry the channel for (like the canadian games on NHL CI)
Technically, they are just re-mapped. During the season they move to the appropriate transponder as needed for that day's games. These moves occur at around 6:20 AM EDT for all of the sports packages. The only ones moving these days are MLBs.
There are about 8 utility channels which are used to get the feeds which are not on RSNs. These channels are shared by NHL Center Ice, NBA League Pass and some of the RSN Alternates. The actual channels have numbers and names such as SKDL(x), but they never show in our EPGs as such.
There are occasions when a SKDL(x) channel is used for MLB Extra Innings. Most of these are when the game is on FSN West 2, since this RSN is not on a ConUS Tp.