Boatspeed
I've found that my 192 will point quite close to the apparent wind but makes a lot of leeway if boatspeed isn't kept up around 4 kts. or more. I think most folks would agree that a shoal keel doesn't often make for a close winded boat and the 192's centerboard is not large so there has to be a good flow of water over it to generate lift.As far as tuning goes, I've followed the instructions in the manual (not the rigging instructions) that came with my boat. They indicate that since the jib is set flying you want the rig tensioned via the luff wire in the jib and the forestay should be almost slack when the jib halyard is winched tight. Even with the halyard tight I see 6 inches or so of luff sag on the jib in 12-15 kts and a fuller sail than I would like. I find that the boat moves best to windward in these conditions if I allow the jib to backwind the main a little. If I sheet the main in tight enough to get rid of the luffing on the leading edge the boat tends to make more leeway without going appreciably faster.I hope this helps,Dave