Scotland are closing in on qualification for next year's European Championship, but manager Steve Clarke believes facing England in a friendly on Tuesday will give a true reflection of how far his side have come.
Clarke's men have won all five of their Euro 2024 qualifiers, including at home to Spain and away to Erling Haaland's Norway.
Scotland's place in Germany could even be sealed on Tuesday should Norway and Georgia draw in Oslo, but they have not beaten old rivals England since 1999.
The clash at Hampden Park in Glasgow is to mark the 150th anniversary of football's oldest international fixture.
England lead the overall head-to-head 48 wins to 41, but have been even more dominant in recent times.
Scotland's 1-0 success at Wembley 24 years ago in a Euro 2000 playoff, which England still won 2-1 on aggregate, is the only time the Three Lions have lost in the last 12 meetings stretching back to 1985.
"Now we see what we can do against a team that's nominally a pot one team, always in the later stages of tournaments," said Clarke of England at his pre-match press conference on Monday.
"That's the benchmark we want to judge ourselves against and we will find out tomorrow night how close we are."
The sides last met at Euro 2020, when a group stage clash ended 0-0.
England went onto reach the final of that competition, losing on penalties to Italy, while Scotland failed to make the knockout stage in their first major tournament for 23 years.
But Celtic midfielder Callum McGregor believes Scotland have made progress during the past two years.
"We are evolving all the time and we've had some big results since the Euros. We are looking really comfortable at this level, home and away. It's just another opportunity for us to show how far we've come," said McGregor.
"These are the types of games you want to be involved. England have big players with big reputations all across the world.
"It's a great game for us to go and test ourselves. As a nation, if we want to continue to make the next step and continually qualify for big tournaments, these are the types of games we have to earmark for performances and results."
