Ackerman is the process of having the inside wheel of a turn at a greater angle than the outside wheel of the turn. This maximizes grip by allowing those tires to track to the differing runout/arc of a turn while the steering wheel is turned a consistent arc.
Ackerman is determined by, looking down on a car from above, drawing a line from the lower ball joint, through the steering joint on each side until they intersect. These lines should converge right about the rear axle create a large triangle.
If you simply reverse the lower ball joints, that Ackerman triangle now converges ahead of the car, which essentially is anti-ackerman. What this does is reverses the angles so the inside wheel does not turn in at enough angle and the outside wheel turns at too great an angle. This creates a very unstable and twitchy feel to the car and can make it nearly undrivable.
The only reasonable alternative not to running Ackerman angles is to run zero Ackerman. This is when the ball joint and steering joint lines are straight and inline with each other and do not intersect. This does introduce additional friction into the inside tire on a turn, but it does not produce the reversed angles that de-stabilize the car. Some competition cars run this arrangement because they aren't as concerned with tire wear and may want the suspension to be a mirror image for parts universalality.
