I get my grill up as high as I can, it gererally sets in around 550 degrees when the charcoal gets going, and my steak goes on. I put the lid in, and count to 20. Now it's not a fast count, but it's 20 seconds give or take a second. Then i remove the lid, flip it over, and repeat.
My steak always comes out just inbetween blue rare and rare based on that chart.