I am one of those weird kinda players that can spot what's going on with a players' game - why they may be missing, or why they are having trouble running out, etc.
I call it a gift, really. But, I suppose it could be annoying to others. lol.
However, I don't ALWAYS share what I see, I usually keep it to myself, or if I do share, I choose my words very carefully. Nothing like telling a CEO or a cocky player or a sensitive player you caught something they can work on to improve their game. So, I gauge when to say something, if to say something, and how to come across the most helpful and effective while NEVER hurting feelings or putting down a player. Always positive.
One thing that has helped me over the years is when someone tells me during a match, "hey, you're not staying down" or "take your time, your rushing your shots." Those tidbits have helped me immensely overcome deficits during matches.
So, when I saw a friend over the weekend miss a pretty normal, easy-type of shot, I watched a few more times and saw he was barely stroking his cue and not taking his time.
So, as I walked by to report my score, I leaned in and said, "you're two-stroking. Take your time." He replies softy so his opponent cant hear, "well, I've been watching the Chinese pros and most all of them do not stroke the ball a lot so I've been trying that out."
I looked at him like he was crazy, and the words that came out of my mouth had no filter at all, just came out: "Um, you're not Chinese."