A masterclass of dogged defensive determination was produced by Sunderland to register a clean sheet at the Emirates last May.
Dick Advocaat’s defence blocked, headed, tackled and scrapped to prevent Arsenal finding a breakthrough, and secure the point Sunderland needed to edge over the finishing line to survival.
But it was the crowning glory of that back four, rather than the dawn of a new era.
As soon as Premier League survival was assured, the planning immediately stepped up a notch to conduct a defensive overhaul of a squad which clearly required investment at the back.
John O’Shea and Wes Brown were in the autumn of their careers, out-of-contract Anthony Reveillere (questionably) wasn’t fancied by Advocaat, Sebastian Coates was only on loan and Santiago Vergini needed to be moved on, even if Sunderland were duty-bound to sign the Argentine.
Subsequently, four of the eight players who arrived at the Stadium of Light in the summer were defenders.
Damningly, three of those four have been considered surplus to requirements by Sam Allardyce in this transfer window.
That’s some statement.
It’s yet another chapter in the epic story of Sunderland transfer fails; those false-economy cheap signings who are cost-price for a reason.
Only Younes Kaboul has passed muster, yet the injury-prone ex-Spurs man has missed just under half of Sunderland’s Premier League schedule so far.
In fairness, Advocaat had his fair share of reservations over Sunderland’s defensive recruits and wanted another centre-half, even though he was happy to sanction the £2m capture of Coates.
The Uruguayan was worth a punt at that price after his performances at the end of last season, but they have proved to be a false dawn.
Advocaat immediately questioned Adam Matthews’ capabilities in the Premier League after his arrival from Celtic, while he publicly admitted that he didn’t know enough about DeAndre Yedlin.
But the openness with which Sunderland played at the start of the season, coupled with Advocaat’s decision to leave out O’Shea, made the Black Cats’ such a soft touch at the back.
When he initially succeeded Advocaat, Allardyce quickly made it clear that improving Sunderland’s resilience was his priority and he was quietly confident that he could fulfil that objective.
Yet Sunderland have emphatically remained the worst defence in the Premier League.
A total of 28 goals conceded in 15 top flight outings, is a decidedly un-Allardyce statistic.
Allardyce was wrong about being able to mould this set of players into a water-tight, solid unit and he’s clearly now lost patience with the soft goals and lapses of concentration continuing.
He’s had to start getting ruthless to bring this side up to scratch and rightly so.
Coates has gone to Portugal, Matthews is being touted around Championship clubs on loan and Sunderland have explored the possibility of terminating Yedlin’s loan deal at the midway point.
None will be a miss.
Let’s face it, the only defender who has genuinely improved under Allardyce’s tutelage has been Patrick van Aanholt, and even his impact has been predominantly at the other end of the field.
Van Aanholt’s goals have kept Sunderland’s survival hopes alive and while his concentration levels remain questionable, he at least is no longer the liability witnessed at the start of the season.
There are no guarantees that Premier League novice Lamine Kone and Arsenal fringe figure Mathieu Debuchy will improve Sunderland’s prospects of registering a clean sheet.
But Kone has been on Allardyce’s radar since his time at West Ham and he is match-fit after 18 appearances in the French top flight this season.
Debuchy would need a few games to get up to speed, yet this is a player who cost Arsenal £12m just 18 months ago.
For all his previous at Newcastle United, Debuchy would be an upgrade and is hungry to impress, with his place in the France squad for the summer’s European Championships on the line.
Let’s not write-off Jan Kirchhoff just yet either despite his harrowing debut.
Whether Sunderland are in the Premier League or the Championship, there will doubtless be a further defensive reshuffle in the summer. Allardyce will build from the back as he assembles a Sunderland side of his own taste.
But Sunderland couldn’t wait that long and gamble on those already on the books to suddenly find some rock-solid cohesion to keep opposing sides at bay.
If they are to stand any chance of beating the drop, Sunderland need to halt the flow of goals and record some clean sheets.
Too many of those brought in last summer have been unable to help in that goal.