In many ways, football is a simple game: the team that scores the most goals wins. Yet in every single match, there are intriguing statistical sub-plots that help make the beautiful game the fascinating spectacle that it is. That's why, each week, takes a look at the numbers behind the results.

Tonight's FIFA World Cup™ qualifiers dominate this week's review, with particular attention paid to the formidable home records El Salvador, Iran and USA will be protecting against Trinidad and Tobago, Korea Republic and Mexico respectively. Aston Villa's ability to storm such fortresses also gains recognition, as does the emergence of a new prodigy at a club desperately searching for a home win.

36 years and five months on from Mexico's last FIFA World Cup qualifying victory on US soil, El Tri will return north of the border this evening aiming to rewrite history. In Sven-Goran Eriksson, the Mexicans at least have a coach with more recent experience of beating USA in their own back yard, with the Swede having overseen a 2-1 friendly win for England back in 2005. However, the Americans' class of '09 go into this regional grudge match on the back of nine successive home wins in FIFA World Cup preliminaries. The venue, Columbus Crew Stadium, has also proved something of a fortress for the US, who remain unbeaten in seven matches at the Ohio arena.

30 matches, four years and four months have passed since Iran were last beaten at home, and with Korea Republic never having won in Tehran, the Taeguk Warriors arrive with history firmly against them. Ali Daei's side are also protecting a nine-match winning run at the 100,000-capacity Azadi and have survived the past 18 months unbeaten in all competitions. However, the last nation to inflict defeat on the Iranians was, you guessed it, Korea Republic, and Huh Jung-Moo's side touch down in Tehran on the back of a 17-match unbeaten run of their own. The South Koreans will also be comforted by the knowledge that, in three previous FIFA World Cup preliminary meetings with Iran, they have yet to sample defeat.

29 goals in 2010 FIFA World Cup preliminaries have left El Salvador second only to Fiji (31) in the South Africa 2010 scoring charts. Although it's now 27 years since they last graced football's biggest stage, this current crop of Cuscatlecos begin the 'hexagonal' stage of their qualifying campaign in good heart. With eight goals, their chief marksman, Rudis Corrales, is currently the region's joint-top scorer alongside Jamaica's Luton Sheldon, and tonight's visitors Trinidad and Tobago will know to expect a tough encounter. The Soca Warriors may enjoy a slight edge in matches between these nations with four wins to El Salvador's three, but in two previous visits to the Central American nation they have failed to muster a single goal.

16 years, 7 months and 2 days was the age at which Daniel Villalba made history on Sunday by becoming the youngest-ever player to represent Argentinian giants River Plate. The Corrientes-born forward, who has already represented his country at youth level, measures in at just 1.59 metres and has been likened in style to the equally diminutive former River star Javier Saviola. Yet Villalba, known as Keko at the Monumental, endured an unhappy competitive debut after replacing Mauro Rosales with 19 minutes of Sunday's match remaining. At the time, Los Millonarios were 2-0 up and seemingly coasting to victory, but the youngster watched helplessly as two stunning long-range strikes - the second of which came two minutes into injury time - handed Colon de Santa Fe an unlikely share of the spoils. River have now gone nine successive games without a win at the Monumental.

7 successive away wins have propelled Aston Villa into title contention and confirmed the Midlands club's threat to the supremacy of England's 'big four'. Having flourished under the astute stewardship of Martin O'Neill, the Villans have taken a foothold in the top four by racking up a club record 51 points from their opening 25 matches. In securing seven straight away wins, O'Neill's side have also achieved something that no team outside this dominant quartet of Manchester United, Chelsea, Arsenal and Liverpool has managed since the inception of the Premier League. The result is that Villa sit third, seven points clear of Arsenal, two ahead of Chelsea and just five behind leaders Manchester United.