No one expects lush growth in mid-winter, but Chelsea have blossomed since the January transfer window. They have a fine signing who has scored twice in four starts for the club. This apparentpredator at Stamford Bridge happens to be the centre-half David Luiz, rather than the £50m Fernando Torres, who is still without a goal since leaving Liverpool.

It is an unexpected turn of events but when a side is winning the struggles of a particular footballer, such as the Spaniard, are more quirk than crisis. Chelsea, mindful of David Luiz, will look back fondly on their work at the start of the year. Supporters were enraptured long before the opener from the Brazilian in Sunday's victory over Manchester City and the cfcuk fanzine had a 4-3-3 formation on the cover, with a picture of David Luiz filling every place in the line-up.

He is a rarity, and not just for his energy or impact. The deals done at the start of the year are struck under pressure. Liverpool would not necessarily have envisaged losing Torres, but when it became unfeasible to hold him against his will they were ready to recruit. It says everything about Luis Suárez's talent that there has been calm over the convalescence of Andy Carroll, who was bought injured from Newcastle United for £35m.

Suárez's disciplinary record was already noteworthy before the attacker bit an opponent while playing for Ajax against PSV Eindhoven last year, yet there has been a relative restraint so far to his time in England, where he has two goals and a single yellow card. With Torres gone, Liverpool had to back their judgment that the Uruguayan's volatility was behind him.

That type of decision-making under pressure ensures that people are engrossed even in the middle of so prolonged a campaign. An examination of the weekend's starting line-ups shows, as anticipated, that the prominent sides did least in the January marketplace. Manchester United recruited Anders Lindegaard, a goalkeeper who has featured only in the FA Cup ties with Southampton and Crawley Town. Arsenal did not make any additions to their first team.

Such serenity is all very well, but it is more gripping to witness crisis management. West Ham have reacted quite well to the danger of relegation and if they squint the club can almost make out a place of safety in the distance. The real clarity of vision, though, has lain with Demba Ba, the Senegal striker who has four goals from half-a-dozen League appearances since moving from Hoffenheim.

He is one of a quartet of noteworthy recruits bought for Avram Grant's team in January. All would have been on the field against Tottenham on Saturday had the rules not prevented Robbie Keane from facing his parent club. By the same token, Arsenal knew that Carlos Vela would not be embarrassing them, even if two goals were still scored against them in the draw at West Bromwich.

The threat of relegation is a great trial of judgment that can make the Premier League riveting even when the competition for the title lacks intrigue. It causes stress in the boardroom as much as the dugout. How much extra is to be spent on wages or transfer fees when a club might still wind up dragging a weight of debt behind them in the Championship?

Extreme measures are adopted in the hope of ducking such a fate and it would seem nearly sensible, say, for a manager to call in a poacher and a central midfielder in January for a combined cost of £24m. Gérard Houllier did that, but while the £18m Darren Bent has three goals for Aston Villa that include a winner over Manchester City, Jean Makoun caused disruption by bringing a ban on himself for a two-footed tackle on Blackpool's DJ Campbell.

In January, desperation can stoke the price of a run-of-the-mill player and the dangers rise steeply as well. While Arsenal pose a challenge to United at the head of the table, that struggle is not likely to reek of the fear that characterises the lower reaches.

That area is also a piece of football territory in which some individuals thrive. The Wolves fans, for instance, know the difference Jamie O'Hara has made since he came from Tottenham in January. It is the fifth loan move of his career, yet in his case there is no sign of disillusionment. Instead the realisation that there is a threat to be countered brings out the best in him.

The call-up for the England squad of Wolves' Matt Jarvis might even suggest that living close to the brink is the making of some footballers. Relegation may be a hideous prospect, but the fear of it galvanises more clubs than the quest for trophies ever can.