4 Wheels vs 6 for games like 2014

[jkelleyrtp]

http://www.chiefdelphi.com/media/papers/1443

This post was more-or-less inspired by the old 4wd physics analysis posted a while back and I was just verifying if any of the old information is pretty much the same considering how much drivetrains have evolved since then.

Based on wheel base sizes, why do so many teams opt for the long chassis? In 2012 I feel that chassis shape would have taken a change for wide, but alas I was not around in FRC back then to see what the trends were.

This year (as rookies) we ran with the KOP chassis and had a significant rock. As our weight distribution ended staying with the part of the robot with the lift, we mainly stayed on the four front wheels the entire time. Has anybody experienced how bad the scrubbing is on long 4wd systems? And would have a 4wd been have feasible in 2014? Thanks for the input.