Real top players - and some of the less gifted as well - are experts in 'reading' their opponents.
I know very well I am not (or maybe I am not trying hard enough).
A friend once said about my abilities in this area: 'You have the table presence of a freshly peeled shrimp.'

My mother taught me how to play bridge in 1972. In those days she was a pillar of the Dutch Ladies Team. Of course at first I made all the mistakes there were to make. She showed great patience in helping me on my way. We played on a club in Lisse (in the middle of South-Holland's bulb field area, next to the world famous Keukenhof flower park), where she, being an international, enjoyed celebrity status.

I will never forget the following incident. With some difficulty we bid 4♥. When it was his turn to bid, West politely asked my mother: 'Who is declaring?'
'He is', she replied, pointing at me, a sweating twelve year old, having trouble holding his cards.
'Double', West said.
I ended up down for minus 500.

My mother was not bothered by my actions. Not even when I bid 3NT over her 3♣ opening, holding a 5-4-4-0 distribution and 14 points. Not being able to enter dummy, I never made a club trick, of course: down four. My mother didn't mind.
As far as I remember she only once made a reproachful remark. It was about table presence. This was the deal:

S/All		♠	8 6 5 2
		♥	K Q 4 2
		♦	A J 2
		♣	8 7
♠	-			♠	K Q J 10
♥	10 9 7 3			♥	A 6 5
♦	10 9 8 3			♦	Q 7 6 5
♣	10 9 6 5 3			♣	A 4
		♠	A 9 7 4 3
		♥	J 8
		♦	K 4
		♣	K Q J 2

Once more I ended up 500 down (soon this became a familiar number).
My mum did not comment at the table (of course she did not). But later, on leaving the table, she asked me in a slightly reproaching tone: 'Didn't you see that man contemplated doubling 3♠?'
I looked at her in amazement. No, I had not seen it. She had. Therefore she would never have raised to 4♠, even though the South hand was strong enough for such a raise.

Now that I come to think of it: she showed this kind of judgement more often.
'East certainly had the ♥K.'
'You could have known South was strong.'
Remarks like these came without further explanation.
If I could have drawn conclusions from the bidding or play (and hadn't...), she would always explain. But sometimes she just 'knew'. If, in such a case, I asked how I could have known she could not really explain.
'Well, it shows, you can tell just by looking at him...'

Well, I could not tell and I never will. Therefore I am somewhat jealous of those who can; they are privileged bridge players.