LONDON -- Rachel Marsh can pinpoint exactly when her Chicago Cubs fandom began. It was one of those groundhog days in lockdown in July 2020 when her friend Sarah, who was video calling from Chicago, told her to put the Cubs-Brewers game on. Intrigued, she watched, and was quickly hooked.

Marsh, a 25-year-old teacher who lives in Kent, England, didn't know the rules, but that was okay: a ton of Google searches and message boards could fix that. She returned to her TV for the rest of the series. Then another series. Within weeks, she was reading about years of the Cubs' failed expectations -- and the one year, 2016, when they finally won. She identified with the pain. Within months, Marsh was all in, arguing with newfound friends about on-base percentages (OBP) and earned run averages (ERA), making baseball memes on Twitter and fawning over her favourite player: No. 44, Anthony Rizzo.

"I'm that kind of sports fan. I'm nerdy with it," Marsh tells ESPN. "Give me those stats. Give me those weird numbers. I love that."

Every Europe-based baseball fan has a different start to their fandom, when their wee small hours of the morning -- the time in the U.K. when games are typically live -- start to involve highlights and scrolling for player trade news. What's interesting about Marsh's introduction to baseball is its timing.

MLB landed in London in 2019 with a ludicrously high-scoring series (the New York Yankees won both games over the Boston Red Sox in a series that saw a staggering 50 runs scored) that captivated fans and threw momentum behind the league's effort to grow its European fan base. However, that hype was soon stopped in its tracks. The COVID-19 pandemic robbed the promise of another London series the following summer, and then the two summers after that. The reduced 60-game schedule in 2020 was a hindrance, too. Throw in the MLB lockout in 2022, and the brakes were pumped even further.

Now, MLB is back with regular-season games in London, and with another rivalry: The Chicago Cubs face the St. Louis Cardinals at the London Stadium in a two-game series this weekend. This series is of high importance to the MLB's European ambitions, symbolised further by the fact that commissioner Rob Manfred will be also in town.

But, after four years away, can the league reignite the initial momentum it had in 2019?

John McGee, one of the founders of the U.K.'s biggest baseball podcast, "Bat Flips and Nerds," remembers the buzz among fans. The podcast was reaching recording numbers, and his social media was blowing up with questions from Brits who wanted to know more about what they'd just seen.

"The games were just extraordinary. Friends of mine who've never been to a baseball game were like: 'Is it usually like this?'" McGee says, laughing. "No, it's so different from this."

Yet just as momentum was building, the COVID-19 pandemic put the whole world, not just baseball, on hold. The MLB season was paused, returning in July -- by which point even the thought of hosting games internationally seemed a stretch when hosting them domestically was challenging enough. While NFL and NBA returned to Europe at the earliest opportunity after international travel became more readily achievable, MLB has taken an extra beat or two to make its comeback across the pond.

"We [fans] kind of got a little bit forgotten about," McGee says.

MLB's Europe office -- led by Ben Ladkin, who took up the role shortly after the 2019 London series -- tried its best to keep fans engaged. They sent care packages to a wide number of British-based fan groups and took a new approach.

"We didn't have the games in 2020 and actually, although being a massive shame and it was obviously not good in any way, it did give us the opportunity to step back slightly and say: 'OK, we've got this first series, how do we build that for the next time we get teams across?'" Ladkin says.

Ladkin's biggest focus was how to get Europeans to pay greater attention to baseball on a daily basis, which is no mean feat in a sport that often asks itself the same question in America. He ramped up changing the league's content offering in Europe, including bringing in familiar faces to introduce fans to the game -- particularly British faces. The league partnered with England cricketer Harry Brook, who trained briefly with the Cardinals to learn how to hit in the big leagues -- spoiler: it's a lot different from cricket -- while England and Australia cricketers Jimmy Anderson and Nathan Lyon will put aside their Ashes rivalry to throw out the first pitch this weekend.

MLB is not alone in trying to set out a stool in London. America's sports leagues have made a continued play to grow their fan bases in Europe in the past decade, with England's capital acting as a repeated landing spot. The NFL has hosted regular-season games with increased success since 2007. The NBA held regular-season games in London between 2011 and 2019 before turning its attention to Paris.

Now, MLB is returning, with an agreement to host further series in 2024 -- between the Philadelphia Phillies and New York Mets. The Yankees are angling to play in Paris in 2025. But London games will continue until 2026, with an eye to grow the games into a three- or four-game series in future. The mission is to make London home.

"I hope this weekend reignites the place of Major League Baseball in the public consciousness because you really felt that for a couple of months in 2019," McGee says.

One of those fans in the new wave since 2019 will be Marsh. The upcoming Cubs games will not be her first. Last summer, she made a pilgrimage to Wrigley Field and saw six games in five days (she also makes keen mention that she left with an above .500 record). Anthony Rizzo remains her favorite player, even after a 2021 trade sending him to the New York Yankees.

These past weeks, it is Marsh who has been subject to many questions from other new fans asking about the sport: the rules, the best place to sit in the stadium, and who will be the best players to watch.

Sometimes, they ask her what team they should support. No prizes for guessing her answer.

"The Cubs!" she says. "But also, just baseball in general. It's about spreading it in the U.K., and I love that even more."