Secretariat ran his only classy rival Sham into the ground with relentless speed and pressure in a head-to-head duel for 6F. Justify's rivals either couldn't match his cruising speed and/or weren't allowed to get to him cos Restoring Hope did a great job! Jusitfy prob could have run fatser - but not much - and both Secretariat and American Pharoah would've beaten hum easily (imo) ..the beauty of it all is that Justify only had to beat the best around at the time ..and only Gronkowski got near him after missing the start.
Secretariat's sectionals below:
Secretariat ran the first quarter mile in 23 3/5, the half mile in 46 1/5, five furlongs in 58 1/5, six furlongs in 1:09 4/5, a mile in 1:34 1/5, nine furlongs in 1:46 1/5 (tying the world record for a 9f race, and there is still 3f to go), a mile and a quarter in 1:59 (faster than his Kentucky Derby time; unheard of), 11 furlongs in 2:11 1/5 (3 seconds faster than Man O' War's 11f Belmont time) and, finally, the mile and a half in 2:24 flat.
Interesting link below shows times comparison Secretariat v American Pharoah (whose time was approx 1.5 secs faster than Justify (2:28:18)
https://www.businessinsider.com.au/american-pharoah-secretariat-belmont-video-2015-6?r=US&IR=T