A criminally undervalued card, Tenma Line can do a TON of work for very little investment.

At first glance this card merely looks like a way to compensate for the unreliability of position-dependent ice like Chum and Inazuma. Making a wonky combo slightly more reliable isn't a bad thing, but deckspace is extremely tight, and you quickly start enacting a sunk cost fallacy. Played solely for that purpose, it's hard to justify Tenma Line.

But now honestly consider just how often you have to play ice in sub-optimal positions. Sometimes it's hard enough to draw ice period, let alone the ice you actually wanted. Sometimes you have to install a Crick on R&D, or a Yagura on a remote. Sometimes the Pop-up Window you installed early on R&D just isn't cutting it 10 turns later when you're getting slammed by Medium or Keyhole, so you want to swap it out with the Tollbooth protecting your currently empty remote.

While some runners just build up a gigantic rig that doesn't care about your board state, most of them spend a lot of time and energy probing your defenses to figure out exactly what they need to get into the server they want. Tenma Line can throw a wrench in those intricate strategies, granting your ice a frustrating amount of fluidity, especially when you don't have enough ice or credits to just keep stacking them on the server that's being attacked.

Consider also:

• Because it's rarely needed early, it's not a card you really need to include more than one of, making it an easy single include (althought for 3 influence it's a tough splash outside of Jinteki)
• The 4 cost means you can almost always leave it completely exposed and most non-Whizzard runners will ignore it. Obviously you can wait to rez it until you actually need it, so it hurts them more than you if it gets trashed.
• This can be a great counter to Blackmail-spamming Valencias who often let you rez your central ice while blackmail-sniping your remotes. Just use Tenma Line to swap those freshly rezzed ice exactly where she doesn't want them to be.
• The list of ice whose position in the server matters might be bigger than you think. Here's a list of ice whose position always matters (situationally that argument can be made for ANY ice):
  • Archangel
  • Archer
  • Bandwidth
  • Builder (I know, this is a bit silly)
  • Bullfrog
  • Burke Bugs
  • Cell Portal
  • Chum
  • Curtain Wall

Yeah, that's only the A through C. I could keep going.

Tenma Line's true utility can be difficult to see in principle, but in practice it will often surprise you. Some decks legitimately don't have space for it, or don't have the right amount or type of ice to justify it, but I would recommend giving it a shot, especially in Jinteki decks. It opens up a lot of strong plays for a relatively small cost, and tends to defend itself.