Prior to SU5 I made some really dicey landings and got rather high scores for them. They seemed to have gone too far the other way. If ground roll is a function of how far you go down the runway after touching down, the user has very little control over that with a plane without reverse thrust. If you land with no throttle at just above stall speed and immediately apply the brakes, the roll distance is simply physics. How you would get a really ground roll low score with those parameters is a bit strange.