If at first you don't succeed, try, try again.
Just not too many times - that crosses the line into bloodymindedness.
And after two abortive attempts to play 3-4-3, it is now time Jack Ross had a rethink.
As much for self-preservation, as anything else.
Because the 1-1 opening day draw against Oxford United has been followed by another 1-1 draw at Ipswich Town and the pressure is mounting.
Following a midweek Carabao Cup jaunt to Accrington Stanley, Sunderland will face old foes and promotion rivals Portsmouth and the atmosphere at the Stadium of Light is likely to be tetchy to say the least.
If they start poorly against Pompey having lined up 3-4-3, the mood will be closer to febrile.
No-one cares what formation you play when you win, but when results - and performances - fall short, every decision a manager makes comes under scrutiny.
Sunderland may have worked on their new formation in pre-season, signings capable of playing in that system may have arrived, but the bottom line is that the Black Cats look uncomfortable in that shape and that is why it has been abandoned mid-match in each of their first two games.
After conceding, back threes have become back fours and in both games the change has wrought an improvement.
Critics of Ross see that as a lack of faith in his own system; backers that he is prepared to be flexible - that he has a Plan B, as they say.
Whichever camp you are in, Ross has found himself having to solve problems that are partly of his own making.
I say partly, because it is easy to blame the system for all Sunderland's ills when that is simply not the case.
It is not the fault of the system that players failed to do the basics right at Portman Road.
It is not the fault of the system that players could not complete simple passes.
And it is not the fault of the system that Sunderland's defenders looked scared of their own shadows.
Plenty of teams have played 3-4-3 and have done so very successfully, so there is nothing intrinsic to the shape that makes it a poor choice.
But if something is not working, it is not working.
I'm willing to cut Ross some slack for starting with 3-4-3 at Ipswich.
It did not work particularly well against Oxford, but maybe that was a one-off.
Away from home at Ipswich it might be different.
Well, it was. It was much, much worse.
Sunderland found themselves trailing to Luke Garbutt's early goal, and they were in danger of being run over by a large blue tractor in the first half.
Ipswich could and should have had the game won by half-time.
Ross switched to a back four before the break, and took off young left-back Denver Hume - who had endured a torrid first period - at half-time, prompting a defensive reshuffle which saw Conor McLaughlin fill in at full-back.
Sunderland were never in the ascendancy in the second half, but nor was it a repeat of the one-way traffic of the first.
And when Marc McNulty capitalised on a terrible mistake by Ipswich skipper Luke Chambers to lay on the equaliser for Lynden Gooch just after the hour, it was a get out of jail free card for the Black Cats.
Viewed in isolation, a 1-1 draw away from home, against a team just relegated from the Championship, and who are tipped as a rival for automatic promotion, is not a bad result.
But set it in the context of the performance, the underwhelming start to the season against Oxford, and the thick cloud of disappointment that has hung over Wearside following last season's failure to win promotion, and it is a different matter.
Sunderland must improve - and quickly.
