Long after the spoils have dried up, the Giants still are paying the price for hitting a jackpot 15 years ago.

The Giants are entering another cycle of free agency and the NFL Draft with the same primary issue they faced each of the previous seven offseasons: A need to identify and secure quality offensive linemen.

Why do they continue to strike out despite changes to the front office, scouting department and coaching staff? What can be done to reverse fortunes in 2019?

The answer to the first question is equal parts reacting at a time when a proactive approach could have made a difference and continually choosing wrong when backed against the wall. The second is more complicated, as NFL insiders told NJ Advance Media.

“O-linemen are like tires on your car,” NFL Network analyst Shaun O’Hara said. “Nobody wants to pay for them when the tread is running low. But when you are stranded on the side of the highway, you wish you spent money on them.”

O’Hara was at the center of a Giants offensive line assembled with mostly spare parts from 2003-05 and upgraded into a luxury package.

The formerly undrafted O’Hara was a bargain free-agent addition, Rich Seubert was an undrafted signing and David Diehl was a fifth-round draft pick. All were in place when the Giants drafted Chris Snee in the second round and gave big money to free agent Kareem McKenzie.

With the group in place that Giants co-owner John Mara today yearns to replicate, they didn’t need to worry about finding offensive linemen from 2005 through 2009 — so they ignored Father Time. The four starters other than Seubert missed 12 total starts during that span, which included winning Super Bowl XLII.

“What we had was special,” said Snee, now a college scout for the Jaguars. “It’s hard to find a collection of five guys who are selfless. It’s hard to find five guys who are in it to win football games."

Injuries and age caught up to O’Hara and Seubert first and the flat-footed Giants did not have solutions in the queue. Three-fifths of the Old Guard still was intact when the Giants won Super Bowl XLVI — still their most recent postseason victory — but all five starters were gone by the end of the 2013 season.

The problem had festered. By trying to create a patchwork offensive line again, the Giants asked to win the lottery twice.

“The teams that address the trenches are successful,” NFL Network analyst Brian Baldinger said. “Every once in a while you can get a little lucky. It takes good foresight and good development. But generally you have to use resources. Tell me who the guy is they drafted and developed.”

Silence is an answer, too.

Offensive line hell is real

Giants general manager Dave Gettleman believes in “quarterback hell” as the space where a franchise is too committed to a passer who is not the long-term answer.

Does offensive line hell exist? There is a track record to show the Giants are living it.

“There are guys that you pay and they don’t pan out,” Snee said, “and you are stuck with them being a body or a cap hit you can’t cut.”

Since quarterback Eli Manning’s first career snap, the Giants have not drafted an offensive lineman who made a Pro Bowl. Snee, selected 33 picks after Manning in 2004, is the last.

In that same timespan, former Giants general manager Jerry Reese used only two first-round picks (Justin Pugh and Ereck Flowers) and two second-round picks (Will Beatty and Weston Richburg) on offensive linemen. Only Beatty signed a second contract with the Giants.

“You can’t draft No. 9 overall (Flowers) and miss,” O’Hara said. "And that turnover can happen with one guy every once in a while, but look at the Cowboys: They drafted Tyron Smith, Travis Frederick, Connor Williams and Zack Martin. That’s investing in a stock and getting a return.”

The Colts — in danger of wasting quarterback Andrew Luck’s prime — became one of the NFL’s best lines in 2018 after mimicking the Cowboys’ blueprint.

The Giants’ returns in free agency are not any better than in the draft: Since the changes began in 2011, they have signed four offensive linemen to contracts worth $15 million or more.

Three of four were cut, including two (Geoff Schwartz and Patrick Omameh) after playing 13 games or fewer. Nate Solder is one year into a four-year deal given by Gettleman that temporarily made him the NFL’s highest-paid blocker.

Pro Bowler Andrew Whitworth of the Rams was interested in 2017 but the Giants said no.

“Here is the issue: If you draft Ereck Flowers that high, you can’t just sweep it under the rug,” Baldinger said. “You know you need help at that position. The problem is you end up overpaying tremendously to get Nate Solder. It doesn’t go away."

The Giants finished the 2018 season with a line consisting of Solder, a rookie second-round draft pick (Will Hernandez) a midseason waivers claim (Jamon Brown) and two formerly undrafted young players (Spencer Pulley and Chad Wheeler).

Manning endured a career-high 47 sacks but Saquon Barkley finished second in the NFL in rushing yards.

“It’s funny," said Schwartz, a Sirius XM NFL radio host. "(People say) when Saquon Barkley had a good game, the offensive line was not the reason why. When he played poorly, it was the offensive line’s fault.”

Injured center Jon Halapio and Brown are examples the Giants find more success identifying overachievers off the scrap heap than when trying to make a big splash.

Gettleman, as Giants pro personnel director, identified Diehl as a draft steal in 2003. Diehl, a Giants employee, declined multiple interview requests from NJ Advance Media.

“You think that (Super Bowl) line is going to be around forever,” Schwartz said. “You bring in all these guys you think are going to be your line and it didn’t happen. It’s an inexact science, developing and hitting on their talent. There is no set way to do it. But a lot of it does depend on coaching, too.”

How to fix it

A former All-Big Ten center, Giants coach Pat Shurmur applies a common life principle to offseason offensive line-building: If you are not getting better, you are getting worse.

“I think you’ve got to always try to upgrade your offensive line to some degree,” Shurmur said, “because when you look around and you start to see teams that are playing bad offense, don’t look at the skill players first. If you can’t block them, then nothing fancy looks good. Nothing normal looks good.”

But if the Giants have missed again and again, what needs to be fixed now?

Schwartz: “You almost have to draft linemen from the same, like, seven (powerhouse football) schools … because they can play right now. It’s so hard now with practice schedules, lack of hitting at practice, lack of offseason training. You draft someone from a smaller school, it just takes time — and there is not much time to work.”

O’Hara: “With offensive line, the type of person you are drafting is just as important as the (skill). We’re a different animal. You have to take pleasure in the process and the pain. It’s not about this guy runs fast. If I turn on the on the film and you are not trying to bury your guy on the ground in college, you are not going to do it in the NFL. My evaluation is I want to meet with the guy and “With offensive line, the type of person you are drafting is just as important as the (skill). We’re a different animal. You have to take pleasure in the process and the pain. It’s not about this guy runs fast. If I turn on the on the film and you are not trying to bury your guy on the ground in college, you are not going to do it in the NFL. My evaluation is I want to meet with the guy and find out if he loves football.”

Snee: “Very few offenses translate to what I did coming out of college. Things have been simplified so much for these guys that it puts them at a disadvantage when they come in. You are not going to find many guys who are willing to bury their face into a block. It’s a lateral game. You need to find a set of athletic traits that you look for and see who has them, and let that vertical part of the game develop.”

Gettleman changed the Giants’ draft process to de-emphasize position specifics in favor of grading “critical factors (such as) ... instincts, competitiveness, strength, explosion, athletic ability." He also changed the methodology of the draft board set up.

The Giants, armed with the No. 2 pick in each of the first three rounds, aced Gettleman’s first draft. They flopped in free agency.

“If you take free agents from other teams, you don’t know the player," Baldinger said. “You don’t know, mentally, how he is going to fit in a system that is different.”

It’s not going to get easier: A generation growing up on social media touchdown highlights has made playing offensive line less appealing than ever at the youth level, says Snee, a father of three boys.

The Giants used 10 offensive linemen and nine starters in 2018. Finding five reliable starters isn’t enough.

“There needs to be more competition: That’s what ultimately drives offensive linemen,” O’Hara said. “The evaluators have got to find the right guys and then you’ve got to find a way to get them on your team somehow. It’s not easy.”

But maximizing the prime years of Barkley and Odell Beckham depends on it.

“If the nerve center isn’t good up front, it doesn’t really matter," Baldinger said. "And the Giants have found out the hard way, you have to build it the right way.”

Ryan Dunleavy may be reached at rdunleavy@njadvancemedia.com. Follow him on Twitter @rydunleavy. Find our Giants coverage on Facebook.