HOUSTON — The debate at this time last year was Jake Arrieta vs. Yu Darvish, Darvish vs. Arrieta. Who was the best starter available, and where was he going?

Turns out both did more harm than good. Arrieta tanked in the second half and so did the Phillies. Darvish hardly pitched and was bad when he did, the combination contributing to the Cubs winding up in the sudden-death wild card rather than division champs.

The best starter addition was not via free agency. The Astros beat the Yankees to Gerrit Cole. It is part of why Houston is still playing and New York isn’t. The Yankees offered a three-prospect deal around Clint Frazier and Nick Solak, the Pirates wanted Miguel Andujar, the Yanks could not find another avenue and Cole enjoyed a top-five Cy Young season for the defending champs.

The coming free-agent starting market has depth, but not greatness — unless Clayton Kershaw opts out, and perhaps not even then since he is not that Clayton Kershaw any longer. Patrick Corbin, J.A. Happ, Dallas Keuchel, Nathan Eovaldi and Charlie Morton (if he doesn’t retire) headline free agency. A Cole-like figure who reached the trade market would elevate the market, especially with so many starter-hungry teams such as the Yankees, Angels, Braves, Phillies, Brewers and perhaps Astros, who have Keuchel and Morton as free agents.

The Mets would be the most obvious team to make things interesting. But they have yet to hire a GM and want to contend in 2019, so the first time a Jacob deGrom, Noah Syndergaard or even Zack Wheeler could be available is July if the Mets are not in the race.

So who then? Some thoughts about a few top starters I could see being available:

Corey Kluber, Indians: Kluber (once the Cy Young results come out this year) will have hit all his contract escalators and be owed $17 million, $17.5 million and $18 million through 2021. His salary climb in 2019 is among the raises that will counteract money exiting for free agents such as Cody Allen, Michael Brantley and Andrew Miller. The Indians already had a team-record payroll in 2018 and, despite a third straight AL Central title, had a 6 percent attendance decline.

Cleveland has acted proactively with aces in the past, trading Bartolo Colon, CC Sabathia and Cliff Lee. President of Baseball Operations Chris Antonetti said at an end-of-year press conference the team will think “out of the box … to put our organization in a better position moving forward.”

The rest of the AL Central is so bad that the Indians could trade Kluber to get younger, less expensive and address shortages in the outfield and bullpen and remain the prohibitive favorites in 2019 behind a rotation that would still have Trevor Bauer, Carlos Carrasco, Mike Clevinger and Shane Bieber. Kluber has been durable and excellent (leads AL pitchers in innings and ERA-plus over the last five years), but did have a knee injury around midseason, turns 33 in April and has pitched poorly the past two postseasons. Cleveland instead could move Bauer or Carrasco, both of whom are free agents after the 2020 season, but together in 2019 they will make slightly more than Kluber by himself.

2. Robbie Ray, Diamondbacks: Arizona is indeed open for business, and the instinct is to think of the famous names, Zack Greinke and Paul Goldschmidt. But Greinke has three years at $95.5 million left, turns 35 next week and has a complete no-trade clause. Goldschmidt will be entering his walk year.

There was a quick association with Goldschmidt and the Yankees and anything is possible, but after seeing Giancarlo Stanton’s transition issues, I would suspect the Yankees would have concerns about bringing in a righty power bat who has played in just a small NL market and is coming off a season of rising strikeouts — especially at a time when they need to protect a prospect base heavily traded from the past 24 months. I can see them using prospects to get a starter, not another bat.

Ray missed two months in 2018 with an oblique injury, had big walk numbers and has been protected by a terrific defensive team. But he is a 27-year-old lefty who has struck out 30.6 percent of the batters he faced over the last three years — among those with 400 innings only Max Scherzer and Chris Sale are better. He is a free agent after 2020.

3. Carlos Martinez, Cardinals: The best free-agent buys were not Arrieta or Darvish at the top of the market; it was the two years at $15.5 million Milwaukee gave Jhoulys Chacin and St. Louis handed Miles Mikolas. Mikolas, combined with Michael Wacha, one more year of Adam Wainwright and a stable of intriguing youngsters led by Jack Flaherty, gives St. Louis the rotation inventory to use Martinez to chase a big bat and bullpen help.

But what does the industry think of Martinez, who was on the DL three times in 2018 for a variety of mainly arm issues and ended up pitching in relief late? He is owed three years at $35 million; five years are $69.5 million if his options are picked up. He is 27 and pitched like an ace in 2015-16 and performed well in 2017.

4. James Paxton, Mariners: Seattle has been in go-for-it mode, having not made the playoffs since 2001 (the longest in the four major sports). But now that GM Jerry Dipoto and manager Scott Servais have contract extensions, would there be more willingness to recalibrate, especially since they have an old, expensive core, few tradable assets and a poor farm system?

Paxton is two years from free agency and, with Scott Boras as an agent, unlikely to do an extension. The lefty just had his healthiest season, but that still meant 160 1/3 innings.

5. Madison Bumgarner, Giants: This has been an organization that has been reluctant to trade homegrown difference-makers or surrender to a rebuild. But the Giants are 50 games under .500 the past two years and about to hire an analytics-leaning GM, who, by training, will say it is a terrible idea to extend Bumgarner, who in 2018 began to show erosion from his heavy workload (walks and hard-hit percentage up, strikeouts down). The best window to trade him has come and gone (the same could be said for the Toronto duo of Aaron Sanchez and Marcus Stroman).

Still, even a diminished Bumgarner with one year at $12 million left remains a good-to-very good starter, and he has the glow of a fearless postseason performer.