Decoding Coach Park Hang-seo's "secret weapon" at the 2018 AFF Cup.

Cong Phuong, Quang Hai... are very good.

It's not just now that the Vietnamese national team has been highly regarded at the 2018 AFF Cup; ever since winning the silver medal at the U23 Asian Championship earlier this year, regional media have had a very different view of Coach Park Hang Seo and his team.

Not only is Vietnam a strong contender for the AFF Cup title with its well-rounded, young, and enthusiastic squad, but the presence of exceptionally talented players like Quang Hai, Cong Phuong, and Van Hau also makes other teams in the region wary.

In other words, it's been quite a while since the Vietnamese national team has been so highly regarded by opponents, and why so many of their players are so familiar with the lineup in an AFF Cup – even their championship win 10 years ago couldn't compare.

This is understandable, because after what Quang Hai, Cong Phuong, and several other players have shown in the past two or three years, they are now the dream of many top clubs in the region, and are all considered key players for the Vietnamese national team to rewrite history since their first championship exactly 10 years ago.

But the best of all is still... Coach Park.

Quang Hai, Cong Phuong, and many other players in the Vietnamese national team are undoubtedly devastating weapons that coach Park Hang Seo has at his disposal. However, for experts, it's a different story, as the key to Vietnam's victory lies with none other than the South Korean strategist.

Coach Park Hang Seo's talent is now seemingly beyond question, as he was one of the first to help Vietnam's youth teams achieve remarkable success in continental competitions, with victories in both the U23 Asian Championship and the Asian Games.

However, what truly earned Coach Park Hang-seo's admiration was his tactical decisions regarding personnel selection at different points in the match and throughout the tournament. And this is the key to the U23 team's success in previous tournaments.

Many goals have come from players coming off the bench, a prime example being the crucial goals from Van Toan and Cong Phuong that helped Vietnam U23 reach the quarter-finals and semi-finals of the Asian Games.

Or, similarly, the personnel changes in the attacking line-up in different matches have been incredibly effective, benefiting many heroes who were considered second-choice or high-class substitutes like Van Duc or Minh Vuong.

Looking back at the journey with the U23 team, it seems that Coach Park Hang-seo's decisions regarding substitutions and playing style in each match have rarely been wrong and have yielded great results.

Of course, this doesn't mean the South Korean strategist has been completely right in his decisions, but at least so far there haven't been any major incidents since the U23 Asian Championship and the Asian Games.

Possessing many talented players is just the beginning of victory; ultimately, the Vietnamese national team's success still depends on Coach Park's tactical approach.

And to say that the best person in the Vietnamese national team right now is coach Park Hang-seo is perfectly valid!