Double Dual System (i.e. 3 Whistle)
 

Just out of curiosity, how many you participate in NFHS 3 Whistle games? In Central Ohio, we have a very limited number of games using the system. A majority of our games employ the Dual System (i.e. 2 whistle). A limited number of the large conferences in Central Ohio using the Diagonal System of Control. How about in your areas???

90% of our Varsity games are DSC. About 55% of JV games are DSC. The rest are Dual System. We don't have the Double Dual or Triple Whistle system here.
All postseason contests are DSC.

In NW Ohio, there are no 3 whistle games. The majority are duals with the big Toledo schools using DSC for varsity only.

In Maine, all high school playoff games are DSC, but most regular season games -- and all sub-varsity -- are dual whistle.