Can stats pick out the Championship play-off winner?

Millwall, Southampton, Middlesbrough or Hull City are just three games away from joining Coventry City and Ipswich Town in next season's Premier League.

The four sides will contest this season's Championship play-offs, getting under way on Friday.

In the semi-finals, Millwall will face Hull over two legs, while Southampton take on Middlesbrough. The winner of those matches will face each other at Wembley for a place in England's top flight and financial benefits worth north of £100m.

But what does play-off history tell us about which team will be best equipped to win the play-offs?

BBC Sport looks at the trends and patterns in the Championship since the second tier rebranded in 2004 to see who could return to England's top flight for next season.

In the 21 play-off campaigns since the Championship era began in 2004-05, the club finishing in third during the regular season has won promotion the most often.

Recent history shows that teams finishing in fourth place are well set up for promotion, too.

The past six Championship play-off winners have all finished in either third or fourth, of which four successful sides have finished in fourth spot.

With nine of the 21 play-off campaigns in the Championship being won by the side finishing third, Millwall are historically the best bet, but fourth-placed Southampton might be a better shout given the recent trend.

As for fifth and sixth place, the most recent fifth-placed club to win promotion were Aston Villa in 2018-19.

You have to go back almost a full further decade to find a sixth-placed club triumphing.

That honour belonged to Blackpool, who earned promotion through the play-offs from that spot in 2009-10.

The table below shows how the Championship play-offs, since 2004-05, has favoured the sides with loftier finishing places in the regular 46-game season.

Historically, the team entering the play-offs with the best attacking record in the regular Championship season go on to win the play-offs almost 50% of the time.

With 10 play-off wins for the best attackers, that would favour Southampton this time, but recent history shows that less prolific attacks have also fared well in the play-offs.

Each of the past five play-off winners have either had the best or the worst attacking records of the four competing teams.

That includes two play-off wins for the lowest scorers - so going on the offensive doesn't always lead to the promised land of the Premier League.

Millwall, who finished this season's Championship in third spot, have scored the fewest goals (64) of the four play-off teams.

Another important metric is how teams have performed defensively throughout the regular season, although it is less dominant than other metrics.

Seven of the 21 play-off winners since 2004 have had the best defensive record, while the second best has produced six winners.

Five of the past six winners have either had the best or second-best defensive records.

This season, Middlesbrough have the best defensive record (47 conceded), while Millwall (49) are just behind in second.

Speaking of a defensive shut-out, since 2004-05 five clubs have ground out a goalless draw in the first or second leg of the play-offs and gone on to win promotion in an eventual final.

During the play-offs themselves, combining attack and defence certainly pays dividends.

Twelve clubs have gone on to win promotion having been the only team to score in a semi-final leg.

Teams with the best regular season home record of the four contenders have won a third of the play-off campaigns in the Championship era.

That favours Southampton, who comfortably have the best home record of this season's four play-off clubs.

But teams with the worst home record have also fared well, with six winners. Three of the past four winners all had the weakest regular season record on their own patch. This year, that is Hull City.

How important is it to grind out results on your travels heading into a play-off campaign?

Well, history points to clubs with a fine away record doing well in the play-offs.

Nine of the 21 play-off winners have finished the regular season with the best away record among the quartet of teams, including in four of the past six seasons.

This term, Millwall have the best away record of the four play-off teams, and also the best away record of the entire division.

While the best away sides have had the most historic play-off wins, two of the past six were won by the side with either the second or joint-second best record.

Middlesbrough have the second best away record of this season's play-off teams, narrowly better than Hull and Southampton.

Another metric that has conflicting results is recent form heading into the play-offs.

Eight of the previous 21 play-off winners have accumulated the most points of the play-off teams from the final 10 rounds of the regular season, including two of the past four winners.

But six Championship play-off winners have won it following the worst end-of-season form prior to the play-offs, including both of the past two winners and three of the previous six promoted play-off sides.

Going into the play-offs, Southampton are comfortably the most in-form side.

Middlesbrough have picked up the fewest points in that time.

While 35 sides have featured at least once in the play-offs since the 2004-05 campaign, one team will be making their Championship play-off debut this year: Millwall.

Southampton and Middlesbrough have both featured recently.

Middlesbrough have a trio of previous Championship era play-off campaigns, but they failed to earn promotion in any of those attempts.

Meanwhile, Southampton were in the play-offs as recently as two seasons ago, beating Leeds United in the final to earn promotion to the Premier League.

Hull, who snuck into the top six after a final-day win, are the side with the best record in the Championship play-offs among this year's crop.

The Tigers have featured twice before and to date they are one of only two sides in Championship play-off history (West Ham are the others) to have been in the play-offs more than once and won promotion every time.

There are cases to be made for all four teams based on historic and more recent metrics.

But the team to follow the most trends of play-off winners in the past are Southampton.

Historically, their attacking threat, home record and end-of-season form favours that of play-off winners in the past. Their fourth-place position and play-off win two seasons ago also favours recent metrics.

Next with the most factors in their favour are Millwall, whose historic league position and away record favours the trend of previous play-off winners. More recently, the Lions also have attacking and defensive records that favour victorious play-off sides.

Middlesbrough have some historic and recent factors in their advantage. While their defensive record is aligned with play-off winners in the past, their away record and end-of-season form follows the trends of play-off winners in recent years.

In sixth and with the smallest chance in terms of history are Hull. Historically, they have the best record of the four teams in the play-offs. Their home form this term - although slightly mediocre - to some extent follows a trend of recent play-off winners.

This article is the latest from BBC Sport's Ask Me Anything team.