One thing to look at for racers like Jackie is how much the opportunity to race in NHRA Div 1 has declined in recent years. It wasn't that long ago that TAD and TAFC racers in Div. 1 had six or seven weekends to race within the division. Now, because of the loss of tracks, it is down to three weekends at three tracks. That gives them three choices: 1) Race only three weekends a year, 2) Drive longer distances to go to other NHRA divisions, or 3) Race IHRA.
Given the combination of higher purses and more convenient locations, the choice seems easy.