I remember watching the very first game under four tackles. I think it was against Barrow in October 1966 in the Floodlit trophy on a rainy night at Watersheddings (that was a rare event!). What a farce of a match it was. Both sides seemed to panic every time they had the ball, knowing that they only had a very limited number of tackles to do anything with it. Matches after this under the new rule improved a little, but six tackles turned into a better option and history has told us it works reasonably well.
You're saying that limited tackles came in as a mid-season rule change? Seriously ?!