"Should", could it mean "if"?

The following text is taken from BBC news online:

---start here---
The Premiership's other representatives in the last 16, Newcastle, will play Real Mallorca and must travel to Spain for the second leg.

Should Liverpool progress to the quarter-finals, they will face a tie against Inter Milan or Benfica.
---finish here---

In my opinion, the word "should" in the "should Liverpool progress..." means "If Liverpool progress..."

Am I correct? If my guess is correct, why the writer of that article use "should" instead of "if"? I mean, is it wrong if I use the word "if" in that kind of sentence?

Thanks.

In that context "should" means "If Liverpool were to...."

Meaning that it is a kind of conditional sentence?

This is where we start talking about the English subjunctive.

simple answer: YES.

>In my opinion, the word "should" in the "should Liverpool progress..." means "If Liverpool progress..."
>Am I correct?

Exactly correct. Both constructions are good and pretty much interchangeable. I think we just use it for a little variety.

Using "should" in this sense is much more British than American. I think "if" is used a lot more by American sportscasters when describing sporting event playoffs and tournaments. The British are probably "more correct" in this particular English language usage, of course. The only American sportscaster I can imagine talking like that British guy is one of the annoyingly proper ones like Greg Gumbel.