Talk about down to the wire. Silvestre Varela of Portugal scores his team's second goal past United States goalkeeper Tim Howard during a World Cup game at Arena Amazonia in Manaus, Brazil, on Sunday, June 22. The goal, scored with less than one minute left to play, led to a 2-2 draw.
(CNN) -- Let the math begin! With every team having played two matches, it's time to start computing every possible variable in which teams like the U.S. and Portugal can make it to the next round.
Oh, if only the Americans were able to hold off the Portugese attack for 27 more seconds yesterday. Portugal could have hopped a flight with Spain back to the Iberian Peninsula.
But alas, it wasn't to be.
While we lament and scribble scenarios into our spreadsheets, here are five things to ruminate over today about this spectacular but surprising World Cup.
1. You're going to need two screens this week
That's because the last games of the group stages are played concurrently -- meaning, two games at the same time.
United States forward Clint Dempsey celebrates after scoring his team's second goal. The goal gave the United States a 2-1 lead, but Portugal stormed back to tie the crucial Group G match.
Portugal's Cristiano Ronaldo played as if his injured left knee was no bother.
Portugal forward Nani jumps for the ball.
Midfielder Jermaine Jones celebrates after scoring the United States' first goal, in the second half.
Cristiano Ronaldo of Portugal reacts after a play. He failed to score on several good opportunities but made a big pass that led to a Portugal goal.
Fabian Johnson of the United States battles Raul Meireles of Portugal.
Clint Dempsey is challenged by several Portugal players during the action on June 22.
Portugal goalkeeper Beto dives for the ball. He kept the United States scoreless in the first half.
Portugal midfielder Raul Meireles and U.S. midfielder Kyle Beckerman tumble during the June 22 match in Manaus, Brazil.
Nani of Portugal scores his team's first goal past U.S. goalkeeper Tim Howard. Portugal took a 1-0 lead in the fifth minute of the match.
United States supporters gather at the Arena Amazonia in Manaus, Brazil. Broadcasters said the heat and humidity were oppressive.
A Portugal fan shows his spirit in Arena Amazonia in Manaus before the start of the Portugal and United States game on June 22.
Yacine Brahimi of Algeria, right, celebrates scoring his team's fourth goal during a World Cup game against South Korea at Beira-Rio Stadium in Porto Alegre, Brazil. Algeria won 4-2, its first World Cup victory in 32 years.
Son Heung-min of South Korea reacts after losing to Algeria.
Djamel Mesbah of Algeria vies for the ball with Lee Chung-yong of South Korea.
South Korea's Son Heung-min shoots and scores his team's first goal.
Hong Jeong-ho of South Korea and Nabil Ghilas of Algeria compete for the ball.
Algeria's goalkeeper Rais M'bohli makes a save.
Algerian midfielder Nabil Bentaleb, second left, competes for the ball with South Korean midfielder Ki Sung-yueng, first left, on June 22.
Islam Slimani of Algeria breaks through South Korean defenses on his way to scoring his team's first goal.
Son Heung-min of South Korea controls the ball against Madjid Bougherra of Algeria.
A South Korea fan cheers shows his support.
South Korea's Koo Ja-cheol reaches for the ball in front of Algeria's Carl Medjani.
Algerian defender Carl Medjani jumps to head the ball.
An Algeria fan shows his support.
Belgian forward Divock Origi reacts after scoring the only goal during a game between Belgium and Russia in Rio de Janeiro.
Belgian defender Toby Alderweireld heads the ball past Russian forward Alexander Kokorin.
Toby Alderweireld of Belgium challenges Maksim Kanunnikov of Russia.
Dries Mertens of Belgium reacts to a play against Russia.
Belgian defender Vincent Kompany heads the ball past Russia's forward Alexander Kokorin.
Axel Witsel of Belgium controls the ball.
Russia's forward Maxim Kanunnikov tumbles.
Kevin De Bruyne of Belgium tries to dodge a tackle by Vasily Berezutskiy of Russia.
Belgian supporters cheer for their team.
Belgium's midfielder Kevin De Bruyne is challenged by Russia's defender Vasily Berezutskiy, left, and midfielder Oleg Shatov.
Russia supporters kiss during the game.
Jan Vertonghen of Belgium and Alexander Samedov of Russia compete for the ball. 
ATTN.!!!: All games MONDAY will be concurrent. DVR one, watch the other! #WorldCup
— Markus (@ebonygent79) June 23, 2014It all began in 1982 when Algeria was on the verge of making the knockout rounds.
Also in their group that year was West Germany and Austria. When they played, the Germans scored. The 1-0 result good enough to send both the Germans and the Austrians through. So, the two teams basically stopped competing. Had Germany scored two more goals (or lost), Algeria would have advanced. (It has to do with goal difference)
Both Austria and Germany said, "No, not us. We didn't cheat." But get this, there were no shots in the final 80 minutes!
So, FIFA wised up. And the next World Cup saw the first simultaneous matches for the last days of group play.
This is an interesting article about a football game between West Germany and Austria in 1982...http://t.co/2NxPi5eR1J
— Sam Power (@sampower) February 25, 2014On Thursday, the U.S. and Germany already know a 0-0 draw would get both through, so you don't think...? Nah, winning the group is too important.
Americans, you're gonna hear a lot about Austria vs West Germany 1982 in the next few days. Just a warning. #workdcup2014
— Sinan Kubba (@SinanKubba) June 23, 20142. There's a lot at stake today (read: pride)
Let's go through today's matches one by one -
Netherlands v Chile:
If you're going to fixate on one match today, this is it. Both teams are phenomenal. Both are already going through. The only question is, which will top Group B? Bragging rights are a good enough reason to put up a great fight.
Brazil v. Cameroon:
Cameroon is playing to not finish 32nd in a 32-team field. The Indomitable Lions? They've been more like The Skittish Kitties. Brazil hasn't exactly set the field on fire either with its performance so far. Still, there's no doubt this matchup is one they'll handily win.
The boots that Neymar will wear for Brazil's game against Cameroon. Wow. 🔥 pic.twitter.com/sCMJ3smSFz
— Transfer Related (@TransferRelated) June 20, 2014Spain v Australia:
Oh how the mighty have fallen. Defending champs Spain have already been knocked out of the contest. So this encounter is basically a test to see if it can salvage some of its pride.
Croatia v. Mexico:
Croatia needs to score to advance to the next round. Not gonna be easy with Mexican goalie Guillermo Ochoa in the way. He's shut out Brazil and Cameroon, and inspired memes like the one where, Ochoa as Gandalf, stands before the goal proclaiming, "You shall not pass."
"You shall not pass!" #BRAvsMEX #WorldCup2014 #WorldCup pic.twitter.com/BLZWvx9AND
— Because I'm Mexican (@Mexican365) June 17, 20143. That putrid racism in soccer? Yup, still there
FIFA is not happy after pictures surfaced of two men who showed up to the Germany v. Ghana game in blackface and "Ghana" written on their shirts.
Dear @FIFAcom why do you do & say NOTHING when racist fans like these show up to the stadium in blackface? pic.twitter.com/FJERy5eDEa
— Football's a Country (@FutbolsaCountry) June 21, 2014Oh, at the same game, a Nazi sympathizer ran onto the field.
The protester ran who onto the pitch during Germany v Ghana was a Nazi (via @BrooksDT) http://t.co/xRI4xybUAa pic.twitter.com/PSr0WGUa5b
— 101 Great Goals (@102greatgoals) June 22, 2014Such a pity because the second half of Saturday's 2-2 draw was, in our opinion, the best 45 minutes of soccer in this tournament.
4. Don't rule the U.S. out just yet
If only the U.S. could have held on for a few more seconds. But it couldn't yesterday. And Portugal made history by racing down field and scoring what ESPN said was the latest World Cup goal ever in regulation.
Cristiano Ronaldo's magical assist to Varela's brilliant header to give #POR a last breath. https://t.co/U0trHQ1EnQ
— TheCRonaldoFan (@TheCRonaldoFan) June 23, 2014You'd think Portugal would be elated, but Cristiano Ronaldo's reaction to the dramatic equalizer was telling. He just looked down at the ground and walked back to midfield. Portugal really needed a win after putting itself in an impossible hole with a 4-0 loss in its opening match against Germany.
Remarkable photo from #usa 2-2 #por. Thousand-plus words. Hats off to the person behind the lens. pic.twitter.com/CxtTrCIxe1
— James Tyler (@JamesTylerESPN) June 23, 2014So how will Group G play out?
Germany and the U.S. each have four points, while Portugal and Ghana each have one.
The Americans would prefer to just beat Germany, which would win the group.
But if the Americans and Germans draw, both go through as they would if Ghana and Portugal tie. But if there are winners in each match, the loser of U.S.-Germany and the winner of Ghana-Portugal will go to tiebreakers, the first of which is goal differential.
Confused? Let's simplify it for you. Just hope the U.S. wins or draws against Germany.
If #GER beats #USA and #GHA beats #POR by more than 1 ... Ghana knocks USA out of the #WorldCup for the third time in a row. #datajournalism
— RAGreeneCNN (@RAGreeneCNN) June 23, 20145. What does the fox say? Gooooal!
How about them Desert Foxes? Algeria's on the verge of qualifying for the knockout round after a 4-2 victory over South Korea yesterday. Four goals for a country that hadn't scored at the finals in 28 years, hadn't won a match in 32. You know how many African teams has scored four goals in a World Cup match? Zero, until now.
This is the first time since 1982 that Algeria have scored more than one goal in a World Cup game. #ALG pic.twitter.com/664vfWkC8g
— 2014 World Cup (@2014WC_Brazil) June 22, 2014As for the Russia-Belgium affair, the less said the better. The Belgians looked tepid for 88 minutes before one of its youngest players scored the lone goal. You know what you call a match that doesn't have a lot of shots? Belgium's coach called it "highly tactical affair."
