The best strategy is looking today forwards and asking which do you expect to be growing at a continued pace a year or more from now. Then place a bet.
I get it.
I tend to put money where i feel it can best go to work both ST and LT (ideally).
My port completely turned over in May. I had a snapshot of my March 21st positions and noted at end of May they were all flat or down except MDB and TTD. The other 5-6 were essentially dead money from march thru end of May.
Luckily for me i didnt stay in them and except for TTD my entire port turned over. Some of these were newer stocks which i felt had ample room to run while my previous port felt peaked out a bit.
My entire port was up 40% in May it turns out.
I would prefer to stay in a stock for 2 years and just read the ERs along the way, but there are things like port rebalancing, valuation, and my personal goals that i am tracking.
Saul may not have set end goals for stocks when he buys them, but that works for him. He also has a completely different port than 18-24 months ago.
I definitely trade too much, but it also forces me to learn and weed out stocks i dont have the highest conviction in.
I recently weeded my watchlist of approx 40-50 stocks down to about 20, including the 10 I own. I still want to reduce that further.
But that is just my process and it may very well be a poor one.
I would argue that i take the time to understand the vast majority of the stocks I buy. Plenty of knowledgeable posters smarter than me here and on NPI, but i notice an awful lot of consistency among stocks many posters state they own.
I just use the boards to think out loud, as i have no one else to really discuss this with. Such is the married with kids life. 
Dreamer