The World Series was an unforgettable showdown between two powerhouse teams, a nightly roller coaster of Astros-Dodgers drama that will never be forgotten.
But the Fall Classic is over, with the Astros winning the first World Series championship in the 56-year history of their franchise. Now, the offseason starts in MLB, and as the nights get colder, the stove gets hotter.
General managers and baseball operations executives from all 30 teams are just beginning the wheeling and dealing that will help shape the rosters for the 2018 season and beyond, as clubs try to get to the autumn stage where the Astros and Dodgers just played.
Starting today at 5 p.m. ET, free agents are allowed to sign with new clubs, and that is when the real intrigue starts. More than 100 players will be eligible to sign with any team, and there are plenty of big names potentially available.
Here's a quick free-agency guide to get the speculative juices flowing as we get ready to look forward to next year:
Who are the headliners?
There is serious star power lined up in this year's class, from big bats and super starters in their prime to a boatload of bullpen studs that figure to garner tons of attention.
A stunning 2017 season might have slugger J.D. Martinez locked in as the top offensive prize of free agency, but other impact hitters set to hit the market include Kansas City's Eric Hosmer, Mike Moustakas and Lorenzo Cain, as well as Carlos Santana, Jay Bruce, Carlos Gonzalez and Zack Cozart.
The list of starters looks great at the top, with Jacob Arrieta and Yu Darvish competing for the headliner billing and a plethora of excellent options beneath them, including Lance Lynn, Chris Tillman, Carsten Sabathia and Jason Vargas.

Closers Wade Davis and Greg Holland (who declined the 2018 player option on the deal he signed with Colorado last offseason) are the top relief options, and other late-inning bullpen options could abound, with Bryan Shaw, Brandon Morrow, Tony Watson and Mike Minor among the possibilities.
But one name could move to the top of the list. Japanese two-way sensation Shohei Ohtani is expected to be posted by the Nippon Ham Fighters of Nippon Professional Baseball. He's only 23 years old, and with a new Collective Bargaining Agreement in place that subjects the pitcher-outfielder to the new international spending limits, pretty much every team could be in play for his services.
Any other intriguing names?
Tons, just like every year. Free-agent position players could include Jose Bautista, Eduardo Nunez, Jonathan Lucroy, Neil Walker, Logan Morrison, Carlos Gomez, Mark Reynolds, Yonder Alonso, Lucas Duda, Michael Saunders, Colby Rasmus, Matthew Holliday, Carlos Beltran, Mike Napoli, Welington Castillo, Mitch Moreland, Howie Kendrick, Chase Utley, Yunel Escobar and more.
Possible starters include Alex Cobb, Doug Fister, Andrew Cashner, Brett Anderson, Matt Garza, Derek Holland, Ubaldo Jimenez, Jeremy Hellickson, Anibal Sanchez, Jaime Garcia, Scott Feldman, Clay Buchholz, Tyler Chatwood and the ageless wonders, Bartolo Colon and R.A. Dickey.
Additional bullpen arms could include Brandon Kintzler, Matt Belisle, Matt Albers, Neftali Feliz, Addison Reed, Luke Gregerson, Pat Neshek, Juan Nicasio, Joe Smith, Huston Street, Anthony Swarzak and left-handers Jake McGee, Brian Duensing, Jorge De La Rosa, Francisco Liriano, Zach Duke and Oliver Perez.
What about international signings?
Ohtani is going to dominate the conversation in this category, and for good reason. He recently had ankle surgery, but if there are no complications, he should be ready to return to the field at some point during Spring Training, if he is posted. Ohtani has a career .286/.358/.500 slash line, with 48 homers in 1,035 career NPB at-bats, and his lifetime pitching line in Japan's premier league is 42-15 with a 2.52 ERA, 13 complete games and 624 strikeouts in 543 innings pitched.

What are qualifying offers?
The system for qualifying offers changes this year as a result of the latest Collective Bargaining Agreement. It works like this: Teams wishing to receive compensation for lost free agents in the form of Draft picks can offer impending free agents one-year qualifying offers worth $17.4 million, which is the average salary of the 125 highest-paid players in MLB. Two caveats: You cannot receive a qualifying offer if you have received one before at any point in your career or if you were traded during the season.
If a player is eligible for a qualifying offer, he must be extended one by his club before today at 5 p.m. ET. He then has 10 days to accept or decline the qualifying offer, and during that time, he can be in contact with other teams to assess his market value. If he accepts the qualifying offer, he signs a one-year deal with his current team at the predetermined salary. If he rejects the offer, he is free to negotiate with any team as a free agent, but the club that signs him is subject to the loss of one or more Draft picks, and his old team will receive Draft pick compensation. For a full breakdown of the compensation rules related to qualifying offers, read here.
Which position has the most talent in free agency this year?
It looks like first base, with plenty of options to beef up lineups. Hosmer leads the way coming off a career year (.882 OPS, 25 home runs, 94 RBIs) at age 28, but Morrison (a career-high 38 homers in 2017), Reynolds (30), Duda (30), Napoli (29), Alonso (28), Santana (23) and Moreland (22) can hit the long ball, too.

Which position is the weakest in free agency this year?
Once again, considering the sheer amount of free agents that will appear on the board, it might be starting pitching. Front-liners Darvish and Arrieta could get five-plus years at $20 million or more per season, and Ohtani is a game-changer. But beyond that, there are question marks when it comes to injury history, age and recent performance with some of the second-tier names like Sabathia, Cobb, and Lynn. Expect a lot of shorter-term deals with incentives as clubs try to bottle up some lightning.
Which teams will be the most active?
You never really know in this category, with "mystery teams" seemingly popping up in every negotiation, but there are some certainties out there. The Cubs will likely need two starting pitchers and have already traded away some of their top prospects in recent years, so they might be more inclined to go the free-agent route. The Red Sox have been aggressive in free agency in recent years and have a void at first base. The Cardinals and Giants have been perennial contenders who fell off the pace in 2017, so expect them to be active as they pursue trips back to the postseason.