[SiR001]

1st you need to know the heat on your grill, different grills = different temps.

typical striploin steak from superstore - for medium rare, at medium-high heat: 4minutes one side, 4minutes other side, let it sit for 5 minutes before serving = medium rare.

for the smaller thickness, decrease the time.

i always take the steak out of the fridge for at least 15-20minutes to have it warm up a bit otherwise you'll need to increase your cooking time

as well the feel of push back will determine how well done it is...you'll figure it out eventually