"Space is what really creates goals," Nelsen said.
Especially when you combine that space with a quickfire counter attack and players who know what to do with it.
While there are many formations and styles of play, the 36-year-old Nelsen sees the trend in elite football today as favouring the counter-attack.
In part, it is in reaction to the possession game favoured by the likes of Spanish powerhouse Barcelona. To counter Barca's tic-tac-toe passing, teams stayed back and packed bodies into their end of the field.
That made it difficult for teams to penetrate. And if the attacking side did make a mistake, suddenly there was space to work with.
Plus players running backwards to defend their goal are at a disadvantage against those running straight at it.
Nelsen remembers going to a coaching clinic more than a decade ago when the possession game was talk of the sport.
"And it was. It was a fantastic way of playing and Barcelona turned it to another level," he said. "But they (coaches) started figuring out 'Well how can we beat this? How can we combat a team that's so good in possession?'
"And these teams realized that if you make the field very small, it's very hard to keep possession in tight areas. And then they found that these possession-based players, that when the ball was won off them, they weren't very good at getting the ball back or weren't very good running back or sprinting."
So if the right kind of players were in place when the possession-based team lost the ball, a counter-attack could be deadly. And even if the counter failed, the possession-based team was expending valuable energy in having to play defence, which took a toll on its offensive game.
That kind of transition game served Germany well in the World Cup, according to Nelsen.
"They murdered the Brazilians," he said of the 7-1 semifinal slaughter.
The Dutch also profited from that style of play at the World Cup.
"When they broke, they broke with (Arjen) Robben and they broke with (Robin) van Persie and they broke with power. And they destroyed Spain (5-1 in the first round)."
Nelsen is quick to note that, as in other sports, it doesn't take long for coaches to figure out how to break down successful strategies. The next phase will involved stopping the counter-attack.
Toronto's goal is to have many ribbons to its bow.
"This is where we're growing and evolving. Can we be good at possession, can we be good at counter-attacking? Can we bunker in for 80 minutes and have four counter-attacks and score two? Or can we have the ball 80 per cent of the time and win 2-0?"
Toronto's style of play will be determined in part to what other teams do. Chicago, for example, fell back because the Fire knew that TFC was dangerous on the counter-attack.
In counter-attacking, a team needs discipline to hold its shape at the back end and pick the right time to try to win the ball. Then it needs good passers (midfielder Michael Bradley) to deliver the ball to a forward (Jermain Defoe) who has the vision to get in the right position and the predatory skills to finish the play.
While Toronto has taken great steps this year — with 11 games to go, it already has four points more than last year's total — Nelsen notes its progress is stop-and-start. The team excels, then hits a plateau for a few games. There is more to learn and improve to reach the next, higher plateau.
As with other sports, soccer has so-called analytics — specialized statistical breakdowns of opponents and the game. Nelsen has such material at his disposal.
But the former Premier League defender is not one to cut corners. He clearly likes checking out the opposition himself, as do his assistant coaches who spend countless hours watching other teams in action.
"You get a feel for it ... You get to feel a guy's heart, his brain. You get to see it with your own eyes."
Nelsen also believes that analytics will always be catching up with the ever-changing game of soccer. While he is open to all tools, he is a firm believer in the analytics of a good coach.
"It's all good and we use it. But we just use analytics with our brains, with our own eyes. All the coaches, because they have watched thousands and thousands and thousands of games in their lives, you then talk about what you saw."
"So you're actually talking through analytics," he added. "Not because it's on a bit of paper, but you're actually doing it by talking. By saying that the left backs a right-footer, so every time it gets to that left back, he cuts in to his right."
In his book, analytics has to be used as a tool in the arsenal not a shortcut. Because when you cut corners, "you miss the best stuff."
"Now you get an analytical guy who watches the games and who's out there with it. Coupled with all his analytics and he bases it on both, now we're talking," said Nelsen
As the game changes, so do game plans.
When Nelsen arrived in MLS, he had his forwards press opposition centre backs — reasoning that not all MLS defenders could handle the pressure and that a miscue in front of goal could lead to a scoring chance. That has changed somewhat since central defenders tend to be split wide more, with a holding midfielder coming back to get the ball.
Pressuring a player who is better at handling the ball than a centre back is not as useful.
At the recent World Cup, the strategy of a three-man backline drew attention. Nelsen sees the trend happening in Italy as well as the Netherlands — not to mention Manchester United under Dutch coach Luis van Gaal — but says players should dictate formation rather than the other way around.
"There is no right or wrong formation," he said.
Plus formations are fluid today, with teams changing shape depending on whether they have the ball or what part of the field they are in.
Toronto play with a back four but when it has the ball in its own end, it will send the fullbacks high and bring Bradley back to start the attack.
"So when you look at it there, it's a three (man defence)," said Nelsen.
Toronto (9-8-6) hosts the New England Revolution (9-12-3) on Saturday.