This was the first championship a g

This was the first championship a girone unico (with only a group).

The division of the championship in two (federal and italian) wasn't formally cancelled. According to the article 2 of the Regolamento dei Campionati 1909-10 (Championship Rules):

« I Campionati Nazionali di calcio sono di I e II Categoria. Quello di I Categoria é suddiviso in Campionato Federale e Campionato Italiano. Al primo possono prendere parte anche giuocatori di nazionalità estera, residenti in Italia, il secondo è riservato esclusivamente ai giuocatori di nazionalità italiana. » ("The National Championships of soccer are: I and II Categoria (I and II Category/Division). The Prima Categoria Championship is divided in: Federal Championship and Italian Championship. In the first one foreign players (if they live in Italy), too, are allowed to play, in the second one only italian players are allowed to play.")
According to La Stampa in an article dated December 24, 1909:

«verrà proclamato campione italiano il Club meglio classificato fra le squadre pure italiane, e campione federale il Club meglio classificato tra le squadre spurie internazionali» ("[at the end of the season] the best placed team among the "pure italian teams" [teams composed only by italian players] will be proclaimed italian champions; the best placed team among the "not pure international teams" [teams composed by foreign players, too] will be proclaimed Federal Champion").
Foot-Ball, the official magazzine of FIGC, in the classification considered US Milanese, Pro Vercelli, Ausonia and Doria as competing to "italian championship" since they were "pure italian teams"; the best placed among them at the end of the season would win the honorific title of "italian champions".

At the end of the season, there was a playoff between Inter and Pro Vercelli for the title of Federal Champion. The playoff was planned for April 24, but 3 players of Pro Vercelli had to play in a military tournament in that day. Pro Vercelli asked for the postponal of the match, but FIGC and Inter refused (since there weren't more other dates available because of the debut of the Italian National team, and because they thought the prorogation was a tactic to buy time to recover injured players). In order to protest, Pro Vercelli decided that the playoff would be played by Pro Vercelli Youth Team (players 11 years old). Result: Inter won easy the playoff 10-3, winning his first title. Pro Vercelli was accused of serious unsportsmanlike behavior by fans who saw the game.

The winner (and "Federal Champion") was Internazionale.

The "italian champion" (honorific title) was Pro Vercelli.

Results (Indonesian) 2:

Ini adalah kejuaraan pertama unico girone (dengan hanya kelompok). Pembagian kejuaraan dalam dua (federal dan Italia) tidak secara resmi dibatalkan. Menurut pasal 2 Regolamento dei Campionati 1909-1910 (Championship Aturan): «Saya Campionati Nazionali di calcio sono di I e II Kategori. Quello di Saya Kategori é suddiviso di Campionato Federale e Campionato Italiano. Al primo possono prendere parte anche giuocatori di nazionalità Estera, residenti di Italia, il secondo è riservato esclusivamente ai giuocatori di nazionalità italiana. »(" The National Kejuaraan sepak bola adalah:. I dan II Kategori (I dan II Kategori / Divisi) Prima Categoria Championship dibagi dalam:. Championship dan Federal Championship Italia Pada pertama pemain asing (jika mereka tinggal di Italia) juga diperbolehkan untuk bermain, dalam satu detik hanya pemain Italia diperbolehkan untuk bermain "). Menurut La Stampa dalam sebuah artikel tanggal 24 Desember 1909:« Verra proclamato campione italiano il Klub meglio classificato fra le squadre italiane murni, e campione Federale il Klub meglio classificato tra le squadre spurie Internazionali »(" [di akhir musim] tim terbaik ditempatkan di antara "murni tim Italia" [tim yang terdiri hanya oleh pemain Italia] akan diberitakan juara Italia; yang terbaik Tim ditempatkan di antara "tim internasional tidak murni" [tim disusun oleh pemain asing, terlalu] akan diberitakan federal Champion "). Foot-Ball, magazzine resmi FIGC, dalam klasifikasi dianggap US Milanese, Pro Vercelli, Ausonia dan Doria sebagai bersaing untuk "kejuaraan Italia" karena mereka "tim Italia murni"; yang terbaik ditempatkan di antara mereka pada akhir musim akan memenangkan gelar kehormatan dari "juara Italia". Pada akhir musim, ada playoff antara Inter dan Pro Vercelli untuk judul Federal Champion. Playoff itu direncanakan untuk April 24, tapi 3 pemain dari Pro Vercelli harus bermain di turnamen militer di hari itu. Pro Vercelli meminta postponal pertandingan, tapi FIGC dan Inter menolak (karena ada tidak lebih tanggal lain yang tersedia karena debut tim nasional Italia, dan karena mereka pikir pengunduran itu taktik untuk membeli waktu untuk memulihkan terluka pemain). Untuk memprotes, Pro Vercelli memutuskan bahwa playoff akan dimainkan oleh Pro Vercelli Youth Team (pemain berusia 11 tahun). Hasil: Inter memenangkan mudah playoff 10-3, memenangkan gelar pertamanya. Pro Vercelli dituduh perilaku tidak sportif yang serius oleh fans yang melihat permainan. Pemenang (dan "federal Champion") adalah Internazionale. The "Juara Italia" (gelar kehormatan) itu Pro Vercelli.