JARRYD Hayne has opened up about the series of events that led to him signing with San Francisco and the daunting 300+ plays he will be forced to learn.

In a revealing interview with breakfast radio host Alan Jones on 2GB this morning, Hayne discussed the steep learning curve he is confronting ahead of his move to the US — including one particularly befuddling NFL manoeuvre called “king-right-trips-iso-three-on-two”

The former NRL poster boy discussed just how close he was to joining the Detroit Lions, the fact that he’s faster than Americans think and his secret Sydney training sessions.

Here are the highlights:

LEARNING 300 DIFFERENT PLAYS

“I know bits and pieces but it’s a different thing when you’re with a team and learning the infrastructure of a playbook. It’s about 300 plays. I’ve had a look at a San Diego playbook from the early 2000s. The basic thing one play can change about 12 different times — from blocking schemes, to running schemes, to passing schemes — one play will change. Quarterbacks will do an audible if they see a defence that doesn’t fit the play and different things like that.”

WHAT IS KING-RIGHT-TRIPS-ISO-THREE-ON-TWO?

“Some of the play calls are pretty tough. This is just one play call I think: it’s king-right-trips-iso-three-on-two. And then if (the quarterback) gets the defence that he thinks knows the play, he’ll go ‘Kill! Kill!’ and then change the play at the line of scrimmage. Then I’ve got to know the kill play as well. With the crowd noise and all that sort of stuff, I’ve got a long journey ahead.”

SECRET SYDNEY TRAINING SESSIONS

“I’ve had a lot of training and a lot of preparation with the UTS boys in the inner west of Sydney. They’ve been great to me. I’d go down there and keep it quiet when I was training with them and have the pads on and the helmet and do different things. I was a middle linebacker, a free safety, but it wasn’t until I went to running back that it clicked and I really gave myself a chance.”

QUICKER THAN THE AMERICANS THINK

“For me, I didn’t really put much emphasis on (speed). I didn’t want to be known as a bloke that was quick. There’s a lot more to it than just running straight and being fast. Even when we were training for it, I would rather run routes and be more crisp on the things that are relied upon more. But with America, they’re very big on stats. When there’s a stat there that they can rely on, it kind of blows up. When I ran the 4.53 sec (over 40 years) I wasn’t too impressed. I ran a 4.47 sec two weeks before. For me, I was more worried about running routes and all that kind of stuff. Speed comes naturally to me.”

53-MAN SQUAD OR PRACTICE SQUAD

“The key thing for me is that I can make the practice squad as well. For the first three years for a rookie, if you don’t make the 53-man roster you can make a practice squad which are the kind of blokes who can come in and fill in positions and obviously when they do oppose sessions you kind of fill in there. It’s kind of a fall back option.”

ON CLOUD NINERS

“It’s a massive franchise. For me, it still hasn’t hit me yet. I thought I was headed to Detroit and the 49ers came in late. They were always there but they came in late and were aggressive with the deal. For me, I was willing to go anywhere.”

HE HAD COMPLETED A MEDICAL FOR DETROIT

“The craziest thing was when I went to San Fran I was a bit hesitant because obviously the media reports Jim Harbaugh was going to go and we wanted to go to a place where the coach obviously had to want me. With Jim going, there was obviously going to be a new coach.

The craziest thing was I actually spent the most time with Jim Tomsula. When we were there ... he was talking to me a lot. I spent time in his office and we chatted for about an hour. He was trying to tell the scout what rugby was like. He was trying to be that kind of mediator explaining what it was like. We got along really well.

It wasn’t until he got the job that I called the agent and said, ‘You wouldn’t believe it. When I was in San Fran this was the bloke I spent the most time with. This is kind of crazy.’

By that stage we’d been through the process with Detroit. I’d done my full medical and we were pretty much waiting for the season to finish and for everything to settle to sign with them. When the 49ers came late, and Jim was still interested and he told me about the special teams coach ... it all fitted together.

It got me from the side because I deadset thought I was going to Detroit.”