The Bullets blitz sends both inside linebackers straight ahead into their gap responsibilities (A for the Sam, B for the Mac). TCU also tags the blitz multiple ways to send the ILB's to different gaps.
The next aspect of the call is Thunder which tells the Safety (SS or WS) to the TE to blitz outside. The final part of the call is Zero Cop. Cover Zero is straight man coverage with no safety help and Cop is a tag that tells the DE to the coverage to man the TE. This is where the Horned Frogs utilizing athletic DL allows them to be creative.
The corners are responsible for the #1 receivers while the 2 safeties have the backs. The right DE is man on the TE.
vs. a Twins set
The Corners are responsible for the split receivers, the safeties have the backs, and the right DE has the TE.
Against a team that flexes their TE or a no TE set the SS has to make a "Switch" call to the DE and play man coverage on a split receiver.
The "Switch" call by the SS puts the DE back in the pass rush. The corners and safeties keep their coverage responsibilities.
Against one back formations with or without a TE the safeties make the adjustments to cover the extra receivers.
This blitz concept allows TCU to rush 6, bring simultaneously pressure to the TE side and inside, load the box with 2 safeties manned on running backs, and utilize the athleticism of their defensive ends.