Some handicappers are highly "technical"...while others are highly "visual". The technical player would lose his mind if you forced him to abandon his figures and study replays...and vice versa.
If you ever got a chance to look at my DRF...you would think that I am a lunatic who spends every waking moment of his life studying the horses. My past performance pages are literally FILLED with hand-written figures...in three different-colored inks. I am very comfortable playing like that, because my figures "speak" to me...but I have come to realize that my style is only one of MANY other effective handicapping styles out there.
There is a horseplayer that I know for over 20 years. We often run into each other at racetracks and OTBs, nod hello to one another...but don't even know each other's names. He buys his racing form at the door, sits all by himself far away from all distraction...and studies the past performances as intently as if the lives of his kids depended on his next bet. He doesn't lift his head until the horses approach the starting gate...at which time he jumps up and dashes to the betting terminal. When he ran off one day...I walked up to his desk and looked at his racing form, out of curiosity. I wanted to see if his handicapping style resembled mine, in any way, shape or form. There wasn't a single mark written anywhere on his racing form. The paper was as clean as if he had just bought it...even though he had it in his possession for hours...and had wagered thousands of dollars while using it. "A lunatic", I thought...except that I later found out that he is perhaps the most successful horseplayer that the Chicagoland-area has ever seen.
Not everything makes sense, folks...