Chelsea last faced Crystal Palace in the early days of Tony Pulis' tenure; since then the relegation-threatened side have adapted to the rather elementary defensive template favoured by Ian Holloway's successor - an approach contrasting with the attack-minded principles of the former Blackpool manager.
Pulis is yet to truly make Crystal Palace the new Stoke, but is coming close in terms of excitement . Just like Stoke matches were horribly boring, so too now are Palace fixtures, with a dour 0-0 against Sunderland two weeks back a good illustration of the direction Pulis has taken the side - towards pragmatism, an emphasis on discipline in defence and quick, direct attacking.
In last week's 1-0 loss to Newcastle, Palace averaged just 27% possession, but that doesn't even necessarily show that they're counter-attacking: indeed, Palace are best simply described as ‘defensive', because attacking often feels like an afterthought for Pulis' side. That's summed up in the statistics: after not keeping a clean sheet in the first eight games of the season, they've since kept opponents scoreless, illustrating the shift in dynamic - but equally, haven't scored in their past three league matches.
In fact, if Palace are to avoid relegation - currently sitting one place outside the bottom three - they'll almost certainly be the lowest scorers ever to survive, having netted just 19 times in the league this season (the next closest, Cardiff, have 26).
Expect Palace, then, to pack their defence against Chelsea and attack very rarely, focusing on getting numbers behind the ball and protecting the defence. It's in this regard they've improved most under Pulis, with the midfield now doing a far better job of creating an organised unit from front to back - even the attackers are expected to help make the side compact, which largely explains the lack of goals.
Formation wise, Pulis' preference is a basic 4-4-1-1, although he's tinkered with 4-5-1 and even a back three in recent weeks. Still without Marouane Chamakh (top scorer with five, and also important in terms of his role in linking up play as the deeper of two strikers) through injury and having recently also lost club record signing Dwight Gayle, Pulis will likely continue with Cameron Jerome upfront - who shares history with Pulis at Stoke, and was signed on loan in January. He tends to be the more advanced striker (if Pulis opts for 4-4-2), looking to get onto second balls and get in behind the defence.
Who plays alongside him is probably Pulis' biggest debate - Joe Ledley or Tom Ince, both January loanees, can theoretically play as the supporting attacker, with Ledley favoured against Newcastle last week, while Glenn Murray, another striker, is a possibility to return from injury.
Pulis might opt for the 4-5-1, though, which sees Ledley withdrawn into a deeper midfield role, allowing captain Mile Jedinak into a holding role, where he can sweep up between the lines. The Australian is a tough, physical destroyer who sets the tone of Palace's strong combativeness in the centre of midfield - he'll look to break up the rhythm of Chelsea's attacks with his tackling and cynical fouls.
His partner is always afforded a little more attacking freedom, whether it be Kagisho Dikgacoi (most likely), Ledley or even Barry Bannan, who generally burst forward to support the attackers - only sporadically, though, and their primary function remains to break up play.
On the right will almost certainly be Jason Puncheon, Palace's busiest attacker (and remarkably, second highest scorer with three goals). He likes to shoot by cutting inside into narrow, right-sided positions (and Chelsea fans will remember his cracking goal for Southampton almost exactly a year ago to the day), but also crosses frequently from deep, as well as working hard to defend that side of the pitch. On the opposite side is Yannick Bolasie, who's less consistent going forward, and could be replaced by either Ince or Ledley.
At the back, Scott Dann has displaced Danny Gabbidon to become the established centre-back partner for Damien Delaney - he's exactly the sort of defender that flourishes when given lots of protection, because it leaves him free to focus on winning aerial duels and making penalty-box clearances and blocks. Delaney, too, is a ‘pure' penalty-box defender, but can be exposed with pace in behind.
To either side of the centre-backs are Joel Ward and Adrian Mariappa, who tuck in very narrow and concede space out wide. Palace like to invite unambitious lofted crosses, confident in their ability to win headers, and Chelsea must not fall into this trap, and instead, any crosses should be driven from the by-line: Mariappa, in particular, can be slow on the turn and will struggle against Eden Hazard's direct running.
Ward is more agile, and also gets forward more often - but unsurprisingly, these are restricted by Pulis's overwhelming emphasis on defensive security. That should be the dominant feature of this clash.