There is no official USGA course rating/slope for the Jimmy Clay green tee setup. When we switched to the green tees in 2010, an estimated course rating/slope was used for handicap determination.
After several tournaments from the green tees, it appeared that the handicaps were too high. Accordingly, an adjustment has been made to the estimated course rating/slope. In terms of difficulty, this adjustment puts the Clay green tees between Lions white tees and Morris Williams green tees.
In practical terms, low handicap players will not notice any difference in their Clay handicaps. Middle and high handicap players will see Clay handicaps of 1-2 strokes lower than with the original estimated course rating/slope.
Austin Senior Golf Association