Rodriguez: Chicago Fire-Toronto FC Supporters' Shield duel one to watch

Sebastian Giovinco - Juninho - Toronto FC - Chicago Fire - action

You might want to mark Saturday, August 19 on your calendar right now.

That day, the Chicago Fire host Toronto FC in MLS regular-season play. It will be their second and final meeting of the 2017 schedule (TFC won the first game, 3-1, back in April), and could become a vital meeting for the Supporters' Shield race.

The two teams are leading the Shield standings, with the Fire taking over pole position on Saturday, as they won 4-0 over the Vancouver Whitecaps and Toronto FC lost 3-1 against FC Dallas.

For much of the season, TFC have been regarded as the frontrunners for the Shield – the prize for the team with the most regular-season points – with defending holders Dallas regarded as their chief contender. But the Fire have largely come out of nowhere to take the lead at about the midpoint of the season.

It's a remarkable turn of events, considering a few short years ago few would expect a Shield battle to possibly come down to Chicago vs. Toronto. Yet here we are, with TFC's roster remodel project and the appointment of Greg Vanney as head coach bearing fruit, with this tea reaching a point of maturity where the MLS silverware will start pouring in. Meanwhile, Chicago's rebuild has been arguably more impressive, with a stated three-year plan already looking like it might be ready to produce trophies – not even two years in.

But given the parity of MLS and speed with which teams' fortunes change, TFC are arguably grizzled veterans, a star-laden team that Vanney has called "the deepest team in the history of the league," coming off a run to MLS Cup in what has been a complete reversal of almost 10 years of disappointment in Ontario. And the Fire are the "new guys" – not really true given the number of experienced players getting minutes these days, but as the team finished at the bottom of the standings for two straight years, few would have predicted the club would be in this spot, this soon.

These narratives are malleable: Both teams have superstars (Sebastian Giovinco, Bastian Schweinsteiger), established MLS stars or stars in the making (Michael Bradley, Jozy Altidore, Nemanja Nikolic) and plenty of good contributors around the field to do their part; they are two teams with young, ambitious head coaches with MLS playing experience (Vanney, Veljko Paunovic) and front offices that seem to know how to build competitive teams in this league.

And here we are.

There is, of course, another half of the season to go, and one or both of these teams might fall off the pace, or another challenger (perhaps New York City FC?) will shoot into the reckoning. But we've seen in recent seasons that the margin for winning the Supporters' Shield is razor-thin – the last two Shields have been decided by goal differential (2015) and two points (2016) – and it's not unreasonable to think it will go down to the wire again this year.

So who you got: trophy-hungry Toronto FC looking for that first piece of MLS silverware after last year's MLS Cup disappointment, or the surprise-yet-steady Chicago Fire coming out of nowhere? Either way, it should be a good battle over the second half of the season, with plenty of reasons to cheer for one team or the other if you're a neutral. And don't forget that showdown on August 19.