“Tip sag” is the degree to which a slice of Neapolitan pizza sags. The tip is usually loaded with hot, gooey cheese. On the pizza blog Serious Eats—Slice, Adam Kuban wrote on May 18, 2004:
 
“After sitting on the pizza pan absorbing moisture, however, no amount of trickery would alleviate the tip sag that often occurs in most pizza crusts after time.”
 
An Eater.com post on March 21, 2013 was titled “Dallas’ Cane Rosso Bashes Yelpers, Tip Sag Haters.” A Twitter discussion followed on the coinage of “tip sag.” Adam Kuban denied coining it (“It wasn’t me. I believe it was in the early days .(JavaScript must be enabled to view this email address). Wish it *were* my coinage”), but others insisted that he did coin “tip sag.”
 
   
Serious Eats—Slice
Sac’s Place Pizza
Adam Kuban
MAY 18, 2004
12:33 PM
(...)
After sitting on the pizza pan absorbing moisture, however, no amount of trickery would alleviate the tip sag that often occurs in most pizza crusts after time.
 
8 July 2005, Newsday (Long Island, NY), “News & Notes: A juicy find in Astoria‎” by Josh Ozersky, pg. B25:
But the plain slice is a nice piece of work, with good cheese and little tip sag.
 
New York (NY) Times—Diner’s Journal
March 3, 2008, 3:47 pm
Saturday in the Bronx
By PETER MEEHAN
(...)
Adam Kuban, overlord of the very fine pizza blog Slice comments on “tip sag” as a measurement of how crisp a pizza is (one observes tip sag by holding a slice by the crust and registering how far the tip of the slice sags without support.) I think he might have described the pizzas at T089 as having moderate to significant tip sag –– which is not to say that a rigid, cracker crisp pizza is the ideal, but that these pies were a little on the floppy side.
   
ActiveRain
Do You Speak Pizza?
Posted by Kristin Johnston,Waukesha County Realtor Buyers Agent,Waukesha Cty WI Real Estate on 09/08/2011 09:52 AM
(...)
Tip Sag:  The tendency of the triangle tip to droop at the center when you life your slice, characteristic of some New York City pies.
 
Neatorama
Tip Sag
David K. Israel • Monday, November 26, 2012 at 9:44 PM
Professional foodie (what a GREAT job, eh?) Josh Ozersky takes us on a guided tour here of NYC’s East Village pizza parlors. I never knew there was a term for it: but wait til you learn about “tip sag” - which is the ratio of sagginess to crust when you hold a slice of pizza in one hand.
 
Twitter
pizzablogger
‏@pizzablogger
Criticizing tip sag on a Neapolitan #pizza is akin to criticizing an India Pale Ale because it’s hoppy. Styles peeps….know your styles.
8:04 AM - 8 Jan 13
 
Eater.com
Dallas’ Cane Rosso Bashes Yelpers, Tip Sag Haters
Thursday, March 21, 2013, by Hillary Dixler
Some Dallas diners aren’t fond of the gooey nature of Neapolitan-style pizza and one pizzeria owner is doing something about it. Eater Dallas reports that Cane Rosso owner Jay Jerrier has added some thoughts on the subject of soggy pizza goodness to the bottom of the menus at the upcoming second location of Cane Rosso. The addendum schools diners on the facts of Neapolitan pizza like “tip sag” and challenges naysayers who just don’t understand the nature of a fork-and-knife kind of pizza.
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“If you’ve never tried authentic Neapolitan pizza, then you probably don’t know about tip sag—the hot, wet, gooey center of the pie that will make the tip of your pizza…sag.”
Cane Rosso White Rock Menu [Photo: Eater Dallas/Facebook]
 
Twitter
raphael brion
‏@raphael_brion
confirm please! RT@akubanI think either@benleventhalor@lockcoined “tip sag”
3:17 PM - 21 Mar 13
 
Twitter
Adam Kuban
‏@akuban
@raphael_brion@benleventhal@LockIt wasn’t me. I believe it was in the early days .(JavaScript must be enabled to view this email address). Wish it *were* my coinage
3:19 PM - 21 Mar 13
 
Twitter
Ben Leventhal
‏@benleventhal
@akubanYou’re too modest, sir. In inventing pizza-blogging, more than plausible ‘tip sag’ was yours.@raphael_brion@lock
4:04 PM - 21 Mar 13