Should my opponent have resigned or should I have accepted a draw?

Knowing when to resign is something I think we as beginners need to learn.

In this game (I played Black) my opponent began with a wayward queen attack which I fended off very well and had a good opening and early middle game. I did miss about four opportunities to checkmate in the middle game according to the computer afterwards. But hey ho. 

To the end of the middle game my opponent was severely down on material, and had I been in that position I would perhaps have offered a draw and if declined would likely have resigned. 

I blundered my last rook towards the end when my opponent only had a King on the board. But I still had a significant amount of material compared to him. After I promoted my first pawn to a queen my opponent offered a draw which I declined as I was again far ahead in material and very soon would arrive at checkmate (being careful not to draw by stalemate). 

My opponent then for some reason just let his/her clock run down and I won on time. 

I found it odd as I believe my opponent should've resigned much earlier. 

What do you think?

resigned 

He has the right to play on, but letting the time run out in a lost position is not ok. So he either should have played on till mate or just resign the game.

I'll respond to the general point rather than some specifics of the game because in this instance it feels like your opponent new they were beat so was making draw offers. Generally players should not feel obliged to resign. A good test of resignation is that you know the position is lost, you know why it is lost, you feel you have nothing to learn from watching your opponent convert, you feel they can convert it, and you dont want to play on. If those tests are met then resign. In the case of a game with many blunders, even if behind in material, I think the 'losing' opponent is justified in playing on if sloppy play leads them to believe their opponent may blunder the advantage in a few moves, particularly if time pressures are looming. On the other hand, if there is plenty of time in the clock and your opponent is rock solid, then you may be confident theyll have no trouble finishing you off.

Yes of course by all means play on, I wouldn't deny anyone that. I played on longer than I ought to have done in some of my games, but resigned as I was fighting losing a battle. 

My opponent in the case let the clock run down from 16:50. I found it odd. 

I don't think I was unsporting in declining a draw however. 

I agree

Interesting. When I have resigned I have met the tests you mention. 

In this game (and I don't expect you to analyse something that will be forgotten in a day or two) do you think my late mid game and end game blundering made him think I might make a series of errors and end in draw?   

Of course that you are not obliged to accept a draw offer. It is your decision to make. It happens sometimes that people will just let the clock run out in a losing position. 

https://support.chess.com/article/627-sportsmanship-policy

So stalling is against sportsmanship rules, but it will happen from time to time. As I am playing long 1 hour per side games mostly, there were instances where I was waiting half an hour for someone's time to run out. Luckily, it doesn't happen too often.

It is feasible to play on hoping for a blunder, possibly due to time pressure.  To simply sit and let the clock run out gives away the chance for such a blunder.  In US Chess rule 18G1 that is explicitly described as unsportsmanlike conduct and you can contact the TD (arbiter) to adjudicate the game (assuming best play by both sides) even if the player is still sitting at the board, and triggering such an adjudication is an easy way to lose a game that the opponent may not know how to win.

Of course, if you are not certain that the position really is a win then letting the opponent's time run out is a way to ensure that the opponent is given a loss as opposed to discovering that there were forced draws available that both of you had overlooked (and adjudication is supposed to use best play by both sides, not just the level of play already demonstrated).

Both sides made sufficient mistakes that the possibility of a stalemate was real at the end. Therefore I don't think it was unsportsmanlike to play it out rather than resign. Letting the time run out rather than make the final move(s) is clearly bad sportsmanship. BTW, on move 45, White has a forced draw if he shuttles the Queen between b5 and e8.

Very slight typo on the move number, but you are correct that 44 Qb5+ Kany, 45 Qe8+ Kb2 46 Qb5+ Kany 47 Qe8+ Kb2 49 Qb5+ is a three-fold repetition draw.

I've managed to draw some games by stalemate when I played people rated 700-800 (https://www.chess.com/analysis/game/live/6070604385), so I guess it's okay to continue the game and hope for a draw. Stalling on the other hand, it's not okay at all and you should probably report stallers. 

I wanted White to continue play - but from 16:50 (on his clock) he just let it run.  Had it only been a couple of minutes I could understand.  Endgames are not my strong suit however and I could easily have fallen into a stalemate. 

I think I played well for the first 20 or so moves. 

if they aren't going to move then they need to resign.

I've only been playing chess for just over a month (first of all the bots and 10 minute games as a guest) and then I signed up last week and have played 10 official games, so I'm new to all of this. 

I was just trying to work out what my opponent was thinking/doing? By letting the clock run down he lost on time the same as if he had resigned. I just didn't see the point of that. 

Interesting. So had he known this he could've forced a draw.

Mind you I did miss a number of checkmates earlier on and blundered my last rook to his King. Beginners eh? 

If a player is making quite a few blunders it suggests that their skills at calculating and visualising moves are weak. They struggle to see ahead. Such a player might easily blunder into a stalemate by not fully seeing which squares around their opponents king are controlled or become controlled on their next move. This might not be exactly how an opponent frames it, I'm trying to put it objectively 😁.

     As you say, you missed checkmate four times. This may well have led your opponent to think you might blunder into stalemate so he was well within his rights to play on. But letting the clock run out for 16 minutes was inexcusable. Remember that making a move is a refusal of a draw offer so if an opponent in a losing position keeps pestering you with draw you can just ignore them and keep playing.

It isn't just beginners.  My peak US Chess rating was over 2100 (figure the FIDE equivalent is CM) and I've made plenty of blunders over the years.  I was working an on-line tournament (as an arbiter) watching the first board in the final round and I saw a GM make a mutual-time-pressure move that allowed mate-in-one, but his GM opponent overlooked it and the game ended up drawn (they shared first and second place).