By Chris Emma–

(670 The Score) The winds of change swept through Wrigley Field last October as Jake Arrieta walked off the mound one final time in this golden era of Cubs baseball.

Arrieta had just pitched 6 2/3 innings of one-run ball in Game 4 of the National League Championship Series to keep the Dodgers from sweeping his Cubs. Fans rose to their feet as Arrieta walked off the mound, knowing well it was likely the end of his dominance in a Cubs uniform.

The prevailing thought after that night at Wrigley was that Arrieta’s demands in free agency would be too high for the Cubs, and that proved to be the case. The clock officially struck midnight on his career in Chicago when the Cubs agreed to a six-year, $126-million deal with right-hander Yu Darvish on Saturday. That deal will be official once a physical is completed.

Ultimately, the Cubs came to Darvish because of a unique market stalemate that saw his price drop below the projections of many. Whether it was Darvish or Arrieta, the Cubs needed to come away with a frontline starter this offseason, and they did just that Saturday.

Baseball Prospectus updated its PECOTA projections to reflect the Darvish signing, adding three wins to the Cubs’ calculations in 2018 to bring them to a 92-win projection. With all due respect to Mike Montgomery, previously projected to be in the rotation before the Darvish acquisition, that seems to be a fair number. With the Dodgers, whom Darvish last pitched for, projected for 99 wins by PECOTA and the NL Central race expected to be competitive, it was clear the Cubs needed to add pitching depth.

The Cubs’ rotation jumped two projected wins to a 16.6 WAR, according to FanGraphs, which puts them fourth in baseball behind only the Dodgers, Astros and Indians — the three other teams to play in a World Series over the last two Octobers.

Just as important for the Cubs is that they’ve secured a rotation for at least the next two seasons — Darvish has an opt-out clause after 2019 — and likely through 2020. With the addition of Darvish, the Cubs can hope to have eliminated the need to deal prospects away for starters as they did to acquire Jose Quintana from the White Sox last July. The Cubs can feel comfortable with their rotation while hoping their young position players revert to the mean or beyond after some regression or stagnation last season.

Epstein built this Cubs team with young position players like Anthony Rizzo, Kris Bryant, Addison Russell, Kyle Schwarber and more, believing that was the best path to build an organization’s foundation. In turn, part of the Cubs’ plan for contention relied upon aggressive moves to acquire starters who weren’t homegrown. Jon Lester signed a six-year, $155-million deal in December 2014, the Quintana trade highlighted last summer and Tyler Chatwood signed a three-year, $38-million deal in December with the Cubs banking on his prospects away from hitter-friendly Coors Field.

Darvish was the missing piece for 2018 and beyond, with the Cubs humbled by the Dodgers last October and the division rival Cardinals and Brewers posing a greater threat in the NL Central. Epstein had to ensure his organization its chances at the division crown and another shot at the defending NL champs in Los Angeles.

The inevitable change brought the Cubs a new frontline pitcher but maintained the same championship hopes in Wrigleyville.

Chris Emma covers the Bears, Chicago’s sports scene and more for 670 The Score 670TheScore.com. Follow him on Twitter @CEmma670 and like his Facebook page.