do u mean dog leg gearbox?
its a special gearbox that has rearranged shift pattern so u can shift faster. The 1st gear for the dogleg is where the 2nd gear is - downward. and 2nd is where 3rd gear is and so forth...
Why?
1st is rarely used on track and most corners are taken with 2nd of 3rd gear. so with this layout, gearshifting time is reduced slightly for better track time.and dog leg gearbox has closer ratio as well....
was widely used in high performance BMWs in the 70's and 80's. they are a rarity nowadays.
http://www.automotiveinfopage.com/BMW_E12/myM535i/images/mine_shift_knob.jpg