why play for a draw? i think you don't have confidence playing higher rated opponents, play for a win.
Best opening for a draw

The games are not in progress - that is why I have posted here. I am considering playing for a draw as the opponent is so highly rated compared to myself that the chances of me getting a win are so small.

The best way to play for a draw is to play the openings you know best and play the best move on the board at any time. Then you will find an opportunity to simplify and use some positional advantage to force both sides into a passive position.
There exist devastatingly unambitious openings, the London System springs to mind as one example. However, do you really think you've got better chances to draw with an opening you've never played, that will take you into unfamiliar positions? Surely better to devote your efforts to Chess Mentor, Tactics Trainer etc to improve your game overall, no?

Sicilian Defense (especially Bucker Variation for black) (B27) has a high drawish chances. But again, there are always rooms for more experience chessplayer to manouvre and look for good tactical chessplay. For those who could see through the game plan, there are still rooms for setting of "pitfall or imbalance" where their opponent may take it for granted.
Most importantly, try to understand the ideas behind your openings and try to stick with it to middlegame. (But unless you had been "side-tracked" by your opponent and got carried away). Middlegame is where there would be lots of tactics coming in with all the "bombastic moves" to get you off your plan so as you would have a weaker endgame. At this time, a better chess player would just "simplify" the game and go for winning endgame. Food for thought.

Petrov defense (black), French defense exchange (white), Ruy lopez exchange (white) all come to mind for drawish openings

Play the best opening your comfterble with. If you don't, you have more of a chance of loosing that wining or even drawing. besides that, rating meens nothing

It is simple by this assumptions:
1. You don't know his opening
2. He does not know your.
Normally a symmetric position is closer to a draw. That is why petrov opening for e4 and queens gambit for d4 has more chance for a draw. The main reason of playing sicilian defence is to play for wining by black pieces. Any players must know it in advance. Good luck.

Play the openings you know and understand best. Why would you have better chances with an opening you don't know or understand?
It's very likely you'll lose, but that's true in any case. And if you play your usual stuff, you'll learn more about what to watch for in it.

In my latest tournament, I have been matched with an opponent 400 points my better. Because of this, I think my best bet is to play for a draw. Could anyone advise the best openings (both black and white) for this, and why you think it is.
https://www.amazon.com/Opening-into-Endgame-Edmar-Mednis/dp/0080269168
In my latest tournament, I have been matched with an opponent 400 points my better. Because of this, I think my best bet is to play for a draw. Could anyone advise the best openings (both black and white) for this, and why you think it is.