Fernando Alonso has branded Formula One "very poor" after announcing that he will not drive in the series next year.
Alonso confirmed on Tuesday that he would leave McLaren at the end of the season and would not be seeking a drive elsewhere on the grid.
The 37-year-old has had a glittering career in F1, winning back-to-back titles in 2005 and 2006 with Renault, the first of which made him the then youngest ever champion.
Alonso, who is in his 17th season in the sport, has won 32 races, amassed 22 pole positions and reached the podium on 97 occasions.
But the Spaniard spoke candidly on Thursday about the reasons behind his decision to focus on other opportunities, saying that he could find "more happiness" elsewhere.
"It's a series that has some positive things and I've been enjoying for 17 or 18 years of my life," said Alonso.
"I achieved much more than what I dreamed when I started in 2001. But right now the action on track is not what I dreamed of when I joined Formula One.
"Most of my announcement went to sadness, or a sad moment of frustration over the last couple of years for the lack of results. I've been racing for 18 years in Formula One, I won two. Arguably 16 years of my life I was frustrated, but that was not the case and it is not the case now.
"I stopped because the action on track in my opinion is very poor.
"In fact, what we talk about more in Formula One is off track. We talk about polemics, we talk about radio messages, we talk about all these things. And when we talk so many times about those things, it's a bad sign.
"It's because the on-track action was very poor that weekend."
Expanding on his frank assessment of the state of F1, Alonso continued: "It used to be difficult to predict what would happen in Spa or Monza. Now you could write down what is going to happen in Spa and Monza.
"We can put down the first 15 positions with maybe one or two mistakes.
"How predictable everything became is tough. We go to Barcelona, we test on the first day in winter testing and you know what you will do until November in Abu Dhabi. It's tough.
"That's what I feel in Formula One now and I think there are other series that maybe offer better action, more joy and more happiness."
Alonso has not provided any concrete plans for his post-F1 career and says he will not hurry into making an announcement, although he has not ruled out a return one day in the future.
"I'm leaving the door open because I'm driving at the best level of my career," he added. "Why close doors if anything can happen in the future?
"I'm still young, I'm not 45 years old. I feel strong and I'm doing 27 races this season.
"My thinking is to stop and that's why I've stopped, but who knows? I have other challenges than the ones F1 can offer right now.
"I will not probably decide or be ready to confirm anything until a couple of months, maybe October or something like that. It's going to be a long wait and a lot of predictions."
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