general principle about leading / probing at any point
You never lead in most situations because you have the middling hands while your opponent has a relatively polarized range (he has hands that have you crushed and some air hands whereas you have midstrength hands that are bluff catchers -> leading here folds out his worse and lets him continue with better = bad choice)
This is because you would typically raise your strongest hands on the previous street (like raising huge pocket pairs preflop or raising 2p/sets on the flop) and the fact that you called on that street instead of raise indicates that you lack those nutted hands.
Thus on the majority of turns, you should not lead even if you turned something strong.
If you end up using a strategy of leading when you hit something, what your opponent could do is to
>Fold vs your leads very often
>Get more aggressive when you check (since your strongest hands are distributed towards the probe bet line instead)
If you end up leading a lot of air on random flops/turns/rivers, your opponent could go super aggressive and start raising or floating a lot.
I think in general it's really hard to balance so I avoid leading in most situations unless the board develops in a way that really improves the caller's range significantly. There are a few classic examples
1. Calling a 3bet pre, board brings 3 middle cards -> 6-7-8
3bettor here rarely has straights, and never has sets (wouldn't 3bet 66-88)
Caller has all straights and sets
If 3bettor bets with AA and faces a raise, he's usually fked against a range of 66-99, T9s. Even 99 has like 40%+ against AA.
Thus AA-QQ would often check back the Flop to pot control. Thus, caller should incorporate leading.
2. Turn lets the middle card pair -> K-Q-3-Q
When the Preflop raiser cbets the flop and the caller calls Flop
>Bettor has very few QX (he usually checks them most of the time)
>Caller has most QX hands (he never folds and never raises)
On this Q Turn, even a hand as strong as AK or AA should usually check the Turn. Thus when you have QX some of the time (as well as some gutshots), you should lead the Turn to prevent IP player from pot controlling Turn so that you can get in 3 streets of betting instead of 2 streets.
There are really few other situations in which where it makes sense to probe bet (even on straight or flush completing Turns) UNLESS you have way more combos of straights and flushes AND opponent is expected to pot control and check a lot. But I would say for most situations, both players should typically have a similar number of flush combos (and maybe caller may have slightly more straight combos after calling Flop but not always significant enough to warrant leading)
In your case there's really no reason to probe bet small - it doesn't achieve anything vs an opponent with a brain. From an exploitative standpoint, in my opinion your small lead will often result in Inducing bluffs. Thus when you make such plays, you should follow through and call down
Bad thing about this particular river though is that it completes QJ
