Cape Town - There is a well-documented and scientific explanation for the oodles of cream invariably rising to the top of a soothing cup of tea or coffee.
And with an equal degree of logic and alacrity, the PSL's traditionally-fancied clubs have returned to the top positions in the Absa Premier League championship race after a strangely topsy-turvey start to the season.
A quick glance at the Premier League table finds Orlando Pirates, Bidvest Wits University, defending champions Mamelodi Sundowns and Kaizer Chiefs in the four leading log places going into the week-end program - and it is from these four clubs most pundits might have imagined at the start of the season that the top team for the 2018/19 championship title will emerge.
And this viewpoint now seems to have been restored after a period in which a financially-troubled and administratively confused club like Bloemfontein City headed the log for a lengthy period with an admirable, if unexpected sequence of successes and other of the proclaimed minnows were overshadowing their more fancied adversaries.
Mind you Chief's current fourth position might be misleading and a little flattering in view of the fact that their points tally of 17 has materialised from 12 matches, with the three clubs above them, Pirates who head the log with 22 points from 12 games; Wits who have 20 points from 10 games and Sundowns with 17 points from their nine matches, infinitely better placed to strike out for eventual Premier League honours.
What is more, Celtic in fifth place have the same number of points as the vastly popular and supported Amakhosi, but from three fewer matches and SuperSport United are only two points behind Chiefs, but from three fewer games.
However, after starting the season without a victory from their five opening games - four draws and a defeat against Wits - Chiefs were at one point in the unthinkable position of actually occupying bottom position in the log and despite a deflating and bitter defeat in the traditional derby against Pirates recently, there have been signs of a revival, with growing confidence and a return of old-fashioned self-belief.
Pirates, indeed, lost two of their opening four games and drew a third, but are now riding on the crest of a wave. So why are the traditionally stronger clubs dominating once more?
It is a case of money to some degree, with the more affluent clubs able to acquire squads with greater depth and skill and as in the case of Pirates, finding the right blend and combined momentum that has taken time, with Chiefs also handicapped in making a late coaching appointment.
And now with Sundowns coming up against Pirates on Saturday in a timely and mouth-watering encounter it would not be particularly surprising if the winner of this key match-up at Loftus Versfeld also ultimately emerges as champions at the end of the season as well.