Former Manchester United manager Sir Alex Ferguson once said that "attack wins you games, but defence wins you titles." The problem is, without reliable goal scorers, a team will never be in a position to put the second part of the theory to the test, and no team has consistently failed to adhere to Ferguson's maxim for success more than his old club.

If you want to drill down into the detail of United's recurring shortcomings, you will find many reasons for their inability to mount a serious challenge for the Premier League over the past decade, but sometimes, a simple answer can be found underneath an avalanche of statistics and data. Manchester United just don't score enough goals.

Five games into the new Premier League season and only three teams -- Crystal Palace (4), Ipswich Town (3) and Southampton (2) -- have scored fewer goals than United, who have managed five so far.

Saturday's 0-0 draw at Palace was the latest example of the team's lack of cutting edge. Against Palace, United created 15 chances and failed to take any of them. In the 3-0 defeat against Liverpool earlier this month, United created eight chances and drew another blank; Liverpool, meanwhile, scored three goals from 11 chances.

While Erik ten Hag's team did register a healthy 3-0 win at Southampton earlier this month, those three goals came from 20 chances. Across the five league games, United have created 68 chances and scored five of them. So United are making chances, but their wasteful finishing is why Ten Hag's team is languishing in 11th position, already losing touch with the leading pack in the Champions League qualification spots. Their strikers simply aren't good enough: midtable quality at a club that used to demand the best.

The United of Ten Hag is failing miserably to follow Ferguson's blueprint, but the same could be said of the sides managed by David Moyes, Louis van Gaal, Jose Mourinho and Ole Gunnar Solskjaer. While each of those managers shoulder some of the blame, both in terms of tactics and team selection, the biggest problem has been a sorry tale of poor recruitment and scouting failures, the club lurching from one bad signing to another.

When Ferguson's teams dominated the Premier League -- and those days are quickly disappearing in the rear-view mirror -- he prioritised the recruitment of world-class strikers throughout his two decades of success. From Eric Cantona in the early-1990s to the Treble winners of Andy Cole and Dwight Yorke, through to Ruud van Nistelrooy, Wayne Rooney, Louis Saha, Cristiano Ronaldo and Robin van Persie, United always had the best of the best up front. It is why the team won so many titles.

Since then United have signed veterans whose best days were behind them -- Radamel Falcao in 2014, Zlatan Ibrahimovic in 2016, Edinson Cavani in 2020, Cristiano Ronaldo in 2021 -- and gambled unsuccessfully on youngsters with the potential to become stars, including Anthony Martial (20 years old when he joined in 2015) and Rasmus Højlund, signed in 2023 (though it's perhaps too early to make such a judgement about the Denmark international.)

The 23-year-old Joshua Zirkzee, signed from Bologna in the summer, is the latest young player to be charged with becoming the answer to Man United's goal-scoring ills.

Even when United have produced from within, it hasn't gone to plan. When Marcus Rashford burst onto the scene it looked like he could be the answer, but he's been inconsistent, reaching double figures for Premier Leagues goals only four times in eight full seasons. He has scored only 13 times in his past 60 appearances.

There have also been the inexplicable panic moves for strikers, such as Odion Ighalo (2020) and Wout Weghorst (2023), who must have believed their lottery numbers had come in when they received the call to move to Old Trafford on loan.

Aside from the 75 million deal to sign Romelu Lukaku, then 24, from Everton in July 2017, United have failed to sign a centre-forward at the peak of his powers since Ferguson recruited Van Persie from Arsenal in the summer of 2012. Lukaku's record of 42 goals in 96 games was better than many have given the Belgium forward credit for, but even Lukaku failed to break the barrier of 20 league goals a season, and that has proved to be an impossible benchmark for every United striker in the post-Ferguson era.

Van Nistelrooy, now Ten Hag's assistant manager, scored 20-plus league goals in four of his five seasons at United, Ronaldo hit 31 in one season, Rooney hit more than 20 on two occasions, while Dimitar Berbatov registered 20 in 2010-11. Van Persie delivered Ferguson's last title in 2012-13 by scoring 26 league goals.

Since Van Persie's impact in 2012-13, the highest tally of league goals in a season from a United player has been 18, reached by Bruno Fernandes in 2020-21 and Ronaldo in 2021-22. Last season marked a new nadir, with Fernandes and Højlund sharing the top scorer billing with just 10 league goals each. So how has it got to this for United, a club that has been defined throughout their glory years by prolific strikers?

Sources have told ESPN that Harry Kane was on United's radar from as early as 2016, but the club never mounted a serious bid. Their concern while pursuing the England captain from Tottenham Hotspur was that Spurs chairman Daniel Levy would either refuse to do business, or only engage in discussions by insisting on an exorbitant transfer fee for the player. United wouldn't pay the 88m Spurs wanted for Kane before he joined Bayern Munich in 2023.

Lukaku was supposed to be the answer, but his bright start under Mourinho faded and he was offloaded to Internazionale two years later, having ended his days at Old Trafford being deployed as a winger by Solskjaer. But despite the glaring need for a world-class centre-forward, United papered over the cracks by signing the likes of Ibrahimovic, Cavani and Ronaldo.

A move for Erling Haaland failed to materialise in 2019-20 because United wouldn't agree to an escape clause when the forward left RB Salzburg. Borussia Dortmund agreed to the clause and he scored 86 goals in 89 appearances across all competitions. He is now ripping up the record books in a Manchester City shirt, on Sunday equalling Cristiano Ronaldo's record as the fastest men's player to score 100 goals for a top European club.

Martial was signed in 2015, but only after United failed to get a deal over the line for Southampton's Sadio Mané, while Højlund arrived after more experienced strikers were rejected in favour.

Sources told ESPN that Napoli's Victor Osimhen was scouted during the 2022-23 season, but concerns were raised over his ability to hold the ball up and also whether Serie A was a strong enough league to truly measure his ability, with Lukaku's prolific form at Inter cited as a reason to be skeptical of Osimhen's real quality. In spite of those concerns about Serie A, United then opted to complete a 72m deal for Atalanta's Højlund, who was just 20 at the time and had scored 10 goals in 34 games for the Italian side.

It was a similar story this summer, with Zirkzee moving for 36.5m despite netting only 14 times in two seasons for the Serie A team. Before signing Zirkzee, United had considered a move for Brentford's Ivan Toney, but sources have said that the England forward was ruled out because he didn't fit Ten Hag's profile for the required striker in that, while boasting an impressive strike-rate, he didn't press defenders energetically enough.

So United now have an attack consisting of two young, unproven forwards from Serie A, plus Rashford, and exciting young wingers in Amad and Alejandro Garnacho who, while showing signs of bright futures, are not centre-forwards capable of leading the line.

Opponents face United knowing they can be more adventurous against them because they are toothless as an attacking force. United conceded more goals than they scored last season and they have conceded as many as they have scored so far this season, all of which is down to the shortcomings up front.

United might be looking more solid at the back under Ten Hag, and their midfield may finally click into shape following the recent arrival of Manuel Ugarte from Paris Saint-Germain to play the holding role, but unless their strikers start to turn draws into victories, United won't win enough games for their defenders to come close to winning them titles.