With the New York Mets (80-71), St. Louis Cardinals (80-71) and San Francisco Giants (80-71) all tied for two wild-card spots, let's start thinking about what happens if there are two- or three-team ties upon the completion of the regular season.

Let's start with the simplest scenario: two teams tie for the two spots, and only home-field advantage is at stake -- not whether a team qualifies for the postseason.

If there's a two-way tie for the two wild-card spots, but no question of which teams are in playoffs, the first tiebreaker is head-to-head record. The second tiebreaker is winning percentage in a team's own division.

The Mets went 4-3 against the Giants in 2016, so the Mets would host the wild-card game on Oct. 5 if those teams tie.

However, the Mets and Cardinals split the season series 3-3. So it goes to the next tiebreaker -- winning percentage against the team's own division.

All 11 of the Mets' remaining games are against NL East foes. And after one more game against Colorado, St. Louis closes its schedule with 10 straight games against NL Central opponents.

Right now, the Cardinals would host a wild-card game against the Mets because St. Louis is 36-30 against the NL Central and the Mets are 33-32 against the NL East. (Consecutive losses to the Atlanta Braves sting that much more with that scenario in mind.)

Mathematically, the Cardinals are going to have a tiebreaker over the Mets at the end of the season, too. After all, if the Mets ended up with a superior division record, they also would have a better overall record and would not be tied.

St. Louis, by the way, won the season series from San Francisco, 4-3. So the Cardinals would host the Giants if those teams tie and the Mets do not qualify.

Anyway, let's move on to a three-team tie, with the Mets, Cardinals and Giants finishing with identical records and only two of those teams ultimately making the wild-card game.

For seeding purposes, head-to-head record is the first tiebreaker. The Mets and Cardinals each went 7-6 against the other two teams, and the Giants went 6-8. As a result, the Mets and Cardinals would have two chances to reach the postseason, while the Giants would only have one.

The Mets and Cardinals would play for the top wild-card seed the day after the regular season. Because they split the season series 3-3, the game would be played at Busch Stadium because of the Cardinals' better in-division record.

The winner of that Mets-Cardinals game then would be the top entrant and host the wild-card game. The loser would get another shot at the postseason. The loser would travel to San Francisco for an Oct. 4 winner-take-all game for the second wild-card spot.

So let's say the Mets, Cardinals and Giants all tie and the division records are frozen where they are now.

It's Mets at Cardinals on Oct. 3 for the top wild-card spot.

The loser then goes to San Francisco for an Oct. 4 game for the second wild-card spot.

The winner of the Oct. 3 game then hosts the winner of the Oct. 4 game in the Oct. 5 wild-card game.

What's the most extreme travel scenario for the Mets? It comes in a three-way tie for the two wild-card spots. The Mets would finish the regular season on Oct. 2 in Philadelphia, then could:

Lose a tiebreaker game on Oct. 3 at St. Louis.

Win a tiebreaker game on Oct. 4 at San Francisco.

Win the wild-card game on Oct. 5 back in St. Louis.

Open the division series at the Chicago Cubs on Oct. 7.

There is one stipulation in the above three-team-tie scenario: Technically, the Cardinals, then the Mets would get their choice of which seed they want to be. In an academic sense, after the Cardinals choose to be the home team in the Oct. 3 game, the Mets could choose a home game against the Cardinals-Giants loser on Oct. 4. But that is highly unrealistic, because it means only one shot at reaching the wild-card game instead of two and condemns the Mets to being the road wild-card team if they should win that game anyway.

The only unanswered question above is what happens if two of the teams finished tied for the second wild-card spot -- behind the No. 1 wild-card team. That's simply a play-in game on Oct. 3. Home-field advantage would be determined first by head-to-head record, so at New York or St. Louis if it's against the Giants. If it's the Mets and Cardinals tying, the better in-division record hosts the game, because they split the season series 3-3.