I was watching a double leg instructional DVD today and it got me thinking about something Ross said on here last week. He said something along the lines of "Kung Fu teaches a lot of inside trips, which in these days of BJJ might not be so smart".
This got me thinking about several things. Is it a problem to teach inside trips, or is it a problem to teach inside trips and not teach guard passes? Sometimes you've got to take what's available to you, and an inside trip will offer you the best solution to your immediate situation. Ending up on top but in guard is preferable to coming out second best in the standup, or being taken down yourself and ending up on the bottom.
Alternatively, is it OK to teach inside trips as long as you use them in the correct context and highlight the potential pitfalls? You know, don't do them from certain clinch positions where it's easy for him to pull guard, try not to go down with them, watch out for his legs etc.
Perhaps most importantly, is it REALLY that much of a problem? If he's good enough at BJJ for it to be a problem he's probably not going to let you inside trip anyway, unless you've managed to really rock him with punches, in which case he's probably going to be just as distracted from gaining guard.
My final thought is "is inside tripping a misunderstood skill, and is the nature of Kung Fu in the modern world partly to blame?" Whenever I work inside trips I either drive them away from me with my arms or have them in a controlling hold. The latter requires a fair degree of skill and sensitivity to practice safely, and the former requires a partner who can fall or mats. The nature of kung fu schools, and the fact that they often don't thrive, means that most training is usually done on hard floors. This then encourages people to control their partner's fall which then draws them to close and into the guard, which then makes thye technique ineffective.