Here we begin the sword in two hands.
Sort of. Really, I am going to skip some stuff and come back later. The part I am skipping is possibly Fiore's most important text on fighting with a sword, so it deserves its own place. I will continue by looking at Tutta Porta di Ferro, on v23, where something quite peculiar strikes me:
"Qui cominzano le guardie di spada a doy man e sono XII guardie. La prima si è tutta porta di ferro che sta in grande fortezza e si è bona di 'spetar ogn’arma manuale longa e curta e pur ch’el habia bona spada non una di troppa longheza. Ella passa cum coverta e va ale strette. Ela scambia le punte e le soy ella mette. Anchora rebatte le punte a terra e sempre va cum passo e de ogni colpo ella fa coverta. E chi in quella gli dà briga grande deffese fa senza fadiga."
"Here begin the guards of the sword in two hands, which are twelve. The first one is Tutta Porta di Ferro, very strong and good for waiting against any handheld weapon (long or short), provided that your sword is of good quality and not too long. This guard parries, passes and comes to the close. She can exchange thrusts and deliver her own. She can also beat thrusts to the ground, always proceeding with a pass and parrying any kind of attack. She can defend without much effort against anyone who picks a fight with her." - Tom Leoni
Now this is interesting. This guard parries, passes, and comes to the close. It can exchange thrusts. It beats thrusts to the ground. Always with a pass and parrying of any kind of attack. Let's take a look at each bit.
It can exchange thrusts. This seems clear enough, and on v26 we have a play and a follow-on play telling us exactly what to do. This is a largo play of course, so it doesn't come to the close like we have been told; however, it does preform a parry and pass. The follow-on play involves a second pass and though in the largo section, it is very much a close play.
It beats thrusts to the ground. My reading of this is the play of breaking the thrust in v26 and r27. The play here tells us to use the same parry and pass from the exchange and it also speaks of beating thrusts to the ground and then immediately go to the close play. This seems quite in line with Fiore's instruction to parry, pass, and close.
It always proceeds with a pass and parry of any kind of attack. This seems to be tied to beating thrusts to the ground but I get caught up on the 'any kind of attack' part. To me this bit is part of the more general instruction that Tutta Porta di Ferro parries, passes and comes to the close. I can only read this instruction to mean that if covering a cut from here, one should enter stretto, covering with a pass, and look to preforming a close play. With this thought in mind let's jump forward to r39 and the plays with the spear.
"Noi semo tre magistri in guardia cum nostre lanze e convegnemo pigliare quelle dela spada. E io son lo primo che in tutta porta di ferro son posto per rebatter la lanza del zugador tosto, zoè che passarò cum lo pe' dritto ala traversa fora de strada, e traversando la sua lança rebatterò in parte stancha. Sì che llo passar e llo rebatter se fa in un passo cum lo ferire, questa è chosa che no se pò fallire."Again we see this pass and parry action. Interestingly, we are given a few more titbits here. First, we are again instructed to beat away the attacks. We are then told that the passing step is 'obliquely out of line' and to cross and beat the attack away. And finally that this passing, crossing, and beating should all occur in one tempo.
"We are three Masters in guard with out lances, and we aptly take the guards of the sword. I am the first who is set in Tutta Porta di Ferro to quickly beat away the lance of the opponent; I will pass obliquely out of line with the right foot, and crossing his lance I will beat it away to the left. As long as you pass and parry in an[a] single step with your strike, this action cannot fail." - Tom Leoni
Bringing these ideas together, it seems Fiore is telling us to always cover from Tutta Porta di Ferro with a pass of the right foot while beating the opposing weapon to the left in one tempo. The only given exception to this is given when defending a thrust from a sword, where by you first accresimento and then may elect to exchange rather then beat.