A blogger explains in December 2009 where he first encountered the portmanteau styched:
Styched, of course, is the combination of stoked and psyched. I can't take credit for it; I first heard it from a cyclingdirt interview with Adam Snyder. And I doubt he made it up, either. If you'd like to try using made-up words, I might also suggest adding "jenvious" to your vocabulary.
*Jenvious won’t be conquering the internet any time soon, mostly because it tries to slap together two words with mutually exclusive meanings: an object of jealousy is something you have but don’t want to share with others, while envy is directed at someone else who has something you don’t but would very much like to have.
You are wondering whether styched is just as nonsensical because it fuses two words, stoked and psyched, not with opposite, but virtually identical meanings.
The use of stoked to mean ‘excited (in anticipation)’ arose in California surferspeak in the early 60s:
Several of the local surfers were stoked to see and meet George who speaks with an interesting Australian drawl. —Surfing 12, 5 (1976), 76.
This figurative usage differs from much earlier ones because it deverbalizes stoked to an adjective and restricts it to a single affect. That emotion can be stoked is hardly a novelty:
Class hatred by the end of 1932 had been stoked to a white-hot pitch and was not confined to the factory-hands, labourers, shop assistants, domestic servants, and casual labourers who constituted the majority of the trades unions' members. — Charles Cunningham, Germany To-day & To-morrow, 135, 1936.
This deterioration of his models stoked Collins with extra zeal. … “I knew,” he remarks, “that if I didn't construct the miniatures pretty soon, it would be virtually impossible to do so. The originals would collapse into heaps of rotting lumber.” — Richard L. Neuberger, “He Builds America's Finest Wagons,” Popular Science, July1953, 85-89, 198-204. COHA
A Midwestern conservative stoked by a strong sense of Lutheran morality, he felt duty bound to leave his personal stamp on the magazine … Richard Pollak, “Time,” Harpers, July 1969, 42–52. COHA
As a fire is stoked with fuel, people — or personified Texas cities — can also stoke themselves with food:
After two days and nights on the trail, and two days in the boat going down the Chagres River, during which Jessie stoked herself regularly with quinine and coffee, she at last caught sight of the masts of the steamer. — William Saroyan, Human Comedy, 1943. COHA
Thereafter, provided that her precious wells have neither gone dry nor pickled her innards in unwelcome brine, durable old El Paso, stoked on sound lunch of chicken mole and fried frijoles, can stretch out her legs and, with a feeling of progress and accomplishment, address herself to a serene and well-earned siesta. — George S. Perry, “El Paso,” Saturday Evening Post 222, 32 (4 Feb. 1950), 30–60. COHA
I would imagine that surfers were more inspired by by the earlier use of stoking emotion rather than, say, some metaphor drawn directly from stoking a beach fire.
As you suggest, by the mid 1960s and early 1970s, psyched had taken on a meaning almost identical to stoked:
The whole family would be psyched to go. By five o'clock on Friday afternoon we' d be on the road driving to the next water-ski tournament. — Bruce and Chrystie Jenner's Guide to Family Fitness, 10, 1978.
But this slang usage didn’t appear out of thin air. Over the course of the 20th century, various discourse groups — especially sports and the military — would get psyched, psyched up, or psyched out, try to psyche/psyche out the competition, or psyche themselves up before a contest as well as being psyched for/about a game. These terms describe a variety of mental states and strategies, not all of them pleasant.
The first slang use of psyched arose in early 20th century among those wealthy enough to afford psychoanalysis:
Well -- she went to this psychoanalyzer she was “psyched,” and biff! — bang! — Home she comes with an unsuppressed desire to leave her husband. — George Cram Cook, Suppressed Desires [play], 1914. COHA
It had become the fashion for whole families to be “psyched,” to be cured of imaginary ills by an imaginary cure. It had, indeed, become a social disgrace not to be “psyched.” — John Cournos, The New Candide, 13,1924.
A slang abbreviation for psychoanalyzed, this usage continued into the 1960s:
He and Lee Matson were going to get married but she wouldn't marry him unless he got psyched. He guessed he needed it all right. — John Dos Passos, Mid Century, 1961.
Let the Games Begin!
One of the first sports/games to adopt the word — independently, I assume — was tournament bridge:
…South psyched the clubs, hoping to get doubled and run out at diamonds. — Syndicated bridge column “According to Cuthberson,” The Daily Colonial (Victoria, BC), 16 Sept. 1939.
South’s club bid was not warranted by the cards; it was designed solely to unnerve, i.e. fake out, the opposing partners. To psyche a suit/bid is still current jargon among bridge players.
This sort of strategy is behind several other uses of the word in competitive sports. Thinking too much about the competition can hamper performance, and one’s opponent may adopt a tactic to force you to do that very thing:
If the mental attitude is nursed and pampered, there is less chance of being “psyched,” the foot racer’s term for being tricked by his own thoughts. — Life Magazine, 3 Dec. 1956.
It was all part of his strategy; his opponent was supposed to be "psyched out" by these maddeningly deliberate movements. But Neal was not "psyched out"; he had found his second wind. When play was resumed he was able to renew his attack and win point after point. — Philip Harkins, Fight Like a Falcon, 74, 1961.
When a player feels he has attained a psychological and intangible edge on another player, he says he has psyched him. It is a sign of these times that people are conscious of one another's psyche. It is a device used most effectively in sports by Cassius Clay… — Zander Hollander, Baseball Lingo, 101, 1967.
Don’t Get Psyched, Get Psyched
A strategy to avoid getting psyched in the negative sense is to get psyched in another — to prepare oneself mentally, a discipline useful not only in sports:
At the end of this performance, Parry describes himself as “psyched” — mentally ready for his best effort. — The MATS Flyer, Volume 6 (1959),13.
As president, he also had to keep the other guys in line, keep them psyched up, ready to help make Archie's assignments work. — Gay Talese, Fame and Obscurity, 1961.
Mason told of young men poised at his helicopter door who “were growling and yelling behind me, psyched for battle. I could hear them yelling above all the noise. I still can.” — Contemporary Authors, 1962.
By this time, I was mentally "psyched" to perform; I made a cross on my forehead and skated out for my first number. — Tina Noyes, Freda Alexander, I Can Teach You to Figure Skate, 116, 1973.
People here were finally psyched up to accept busing and integration. — Richard Harris, “Talk of the Town,” New Yorker, 11 March 1972, 27–31. COHA
Mental perparation can be as free of affect as an airplane pilot concentrating on a mission or as laden as screaming soldiers drowning out the sound of helicopter blades. The constitutive factor here is the preparation. In fact, in the last example, psyched up hardly carries any other meaning than prepared. To get to the fun exciting psyched, you have to look elsewhere.
Psyched as Mental State
In a more general use, being psyched can simply mean ‘in an agitated, worrisome, or fearful state’:
This guy's got me psyched. I can't land him. I've offered him everything. — Garson Kanin, Come On Strong [play], 1962. COHA
Finally, Jimmy called his father and told him he was coming home. The day he left, he was all “psyched up,” Jimmy's friend said. " He was like a cat, Really afraid of what he would face when he got home. But I told him nothing could be worse than what he was going through. — Bill Kovach, “Sailor Back from Exile a Symbol of Deserters’ Plight,” New York Times, 27 Dec. 1971. COHA
Just as hyperbole can render mad or crazy into an exciting and quite positive emotion, so someone can be psyched by an upcoming waterskiing vacation. Anxiety becomes anticipation. This is not, however, the source of the second half of of the portmanteau styched.
Now a figure skater, a sprinter, or a mountain biker only competes indirectly with others. Performances are ultimately individual. The mental preparation necessary for the best time or score may have no outward sign of emotion, but if you want to add anticipation and excitement to the mix, and if you have a rather undeveloped sense of language, you can end up with styched. This neologism may be lots of things, but it isn’t a tautology.